Fujitsu S920 slowing down uplink

I got a Fujitsu S920 with AMD GX-222GC and naturally I installed OpenWrt.

The specs are:
FUJITSU FUTRO S920/D3313-G1, BIOS V4.6.5.4 R1.16.0 for D3313-G1x 08/13/2018
AMD GX-222GC SOC with Radeon(TM) R5E Graphics (family: 0x16, model: 0x30, stepping: 0x1)
dell x3959 intel pro/1000 PT dual-port gigabit ethernet
4G ram, 32M reserved for video
8G mSATA

after fighting with some instability issues that you can find discussed here : Fujitsu Futro S920 + OpenWrt random reset now I found a different problem, the uplink is slowing down after a while. If after reset I can get +800Mbit/sec after a while the max is 140Mbit/sec.
A reset fixes the problem for a while - I have not determined the exact amount of time it takes to slow down, but if I start it in the morning a test in the evening shows the slow down on the uplink.
The downlink is still fine.

Below the dmesg output,
Any ideas on how to debug the problem ?
I could not find anything relevant in the logs.

BusyBox v1.35.0 (2022-07-06 19:09:39 UTC) built-in shell (ash)
  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 -----------------------------------------------------
 OpenWrt 22.03.0-rc5, r19523-bfd070e7fa
 -----------------------------------------------------
root@OpenWrt:~# dmesg
Linux version 5.10.127 (builder@buildhost) (x86_64-openwrt-linux-musl-gcc (OpenWrt GCC 11.2.0 r19523-bfd070e7fa) 11.2.0, GNU ld (GNU Binutils) 2.37) #0 SMP Wed Jul 6 19:09:39 2022
Command line: BOOT_IMAGE=/boot/vmlinuz root=PARTUUID=1d323d65-02 rootwait console=tty0 console=ttyS0,115200n8 noinitrd
x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers'
x86/fpu: Supporting XSAVE feature 0x002: 'SSE registers'
x86/fpu: Supporting XSAVE feature 0x004: 'AVX registers'
x86/fpu: xstate_offset[2]:  576, xstate_sizes[2]:  256
x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'standard' format.
BIOS-provided physical RAM map:
BIOS-e820: [mem 0x0000000000000000-0x000000000009e7ff] usable
BIOS-e820: [mem 0x000000000009e800-0x000000000009ffff] reserved
BIOS-e820: [mem 0x00000000000e0000-0x00000000000fffff] reserved
BIOS-e820: [mem 0x0000000000100000-0x00000000d98d2fff] usable
BIOS-e820: [mem 0x00000000d98d3000-0x00000000d997ffff] reserved
BIOS-e820: [mem 0x00000000d9980000-0x00000000d9991fff] ACPI data
BIOS-e820: [mem 0x00000000d9992000-0x00000000d9ad3fff] ACPI NVS
BIOS-e820: [mem 0x00000000d9ad4000-0x00000000dc1c6fff] reserved
BIOS-e820: [mem 0x00000000dc1c7000-0x00000000dc1c7fff] usable
BIOS-e820: [mem 0x00000000dc1c8000-0x00000000dc1cffff] ACPI NVS
BIOS-e820: [mem 0x00000000dc1d0000-0x00000000dc338fff] usable
BIOS-e820: [mem 0x00000000dc339000-0x00000000dcbd3fff] reserved
BIOS-e820: [mem 0x00000000dcbd4000-0x00000000dcc2cfff] usable
BIOS-e820: [mem 0x00000000dcc2d000-0x00000000dcfe3fff] reserved
BIOS-e820: [mem 0x00000000dcfe4000-0x00000000dcffffff] usable
BIOS-e820: [mem 0x00000000fec00000-0x00000000fec01fff] reserved
BIOS-e820: [mem 0x00000000fed00000-0x00000000fed00fff] reserved
BIOS-e820: [mem 0x00000000fed40000-0x00000000fed44fff] reserved
BIOS-e820: [mem 0x00000000fed50000-0x00000000fed50fff] reserved
BIOS-e820: [mem 0x00000000fed80000-0x00000000fed8ffff] reserved
BIOS-e820: [mem 0x00000000ff000000-0x00000000ffffffff] reserved
BIOS-e820: [mem 0x0000000100000000-0x000000011effffff] usable
NX (Execute Disable) protection: active
SMBIOS 2.8 present.
DMI: FUJITSU FUTRO S920/D3313-G1, BIOS V4.6.5.4 R1.16.0 for D3313-G1x 08/13/2018
tsc: Fast TSC calibration using PIT
tsc: Detected 2195.888 MHz processor
e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
e820: remove [mem 0x000a0000-0x000fffff] usable
last_pfn = 0x11f000 max_arch_pfn = 0x400000000
MTRR default type: uncachable
MTRR fixed ranges enabled:
  00000-9FFFF write-back
  A0000-BFFFF write-through
  C0000-CFFFF write-protect
  D0000-E7FFF uncachable
  E8000-FFFFF write-protect
MTRR variable ranges enabled:
  0 base 0000000000 mask FF80000000 write-back
  1 base 0080000000 mask FFC0000000 write-back
  2 base 00C0000000 mask FFE0000000 write-back
  3 base 00DE000000 mask FFFE000000 uncachable
  4 disabled
  5 disabled
  6 disabled
  7 disabled
TOM2: 000000011f000000 aka 4592M
x86/PAT: Configuration [0-7]: WB  WC  UC- UC  WB  WP  UC- WT
e820: update [mem 0xde000000-0xffffffff] usable ==> reserved
last_pfn = 0xdd000 max_arch_pfn = 0x400000000
found SMP MP-table at [mem 0x000fd6e0-0x000fd6ef]
Using GB pages for direct mapping
ACPI: Early table checksum verification disabled
ACPI: RSDP 0x00000000000F0490 000024 (v02 FTS   )
ACPI: XSDT 0x00000000D9983080 00007C (v01 FTS    D3313-G1 01072009 AMI  00010013)
ACPI: FACP 0x00000000D9989EC8 00010C (v05 FTS    D3313-G1 01072009 AMI  00010013)
----- deteted many lines here
rcu:     RCU restricting CPUs from NR_CPUS=512 to nr_cpu_ids=4.
 Tracing variant of Tasks RCU enabled.
rcu: RCU calculated value of scheduler-enlistment delay is 10 jiffies.
rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=4
NR_IRQS: 33024, nr_irqs: 1000, preallocated irqs: 16
spurious 8259A interrupt: IRQ7.
Console: colour VGA+ 80x25
printk: console [tty0] enabled
printk: console [ttyS0] enabled
ACPI: Core revision 20200925
clocksource: hpet: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 133484873504 ns
APIC: Switch to symmetric I/O mode setup
..TIMER: vector=0x30 apic1=0 pin1=2 apic2=-1 pin2=-1
clocksource: tsc-early: mask: 0xffffffffffffffff max_cycles: 0x1fa7065c0d8, max_idle_ns: 440795281550 ns
Calibrating delay loop (skipped), value calculated using timer frequency.. 4391.77 BogoMIPS (lpj=21958880)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 8192 (order: 4, 65536 bytes, linear)
Mountpoint-cache hash table entries: 8192 (order: 4, 65536 bytes, linear)
BIOS may not properly restore RDRAND after suspend, hiding RDRAND via CPUID. Use rdrand=force to reenable.
LVT offset 1 assigned for vector 0xf9
Last level iTLB entries: 4KB 512, 2MB 8, 4MB 4
Last level dTLB entries: 4KB 512, 2MB 256, 4MB 128, 1GB 0
Spectre V1 : Mitigation: usercopy/swapgs barriers and __user pointer sanitization
Spectre V2 : Mitigation: Retpolines
Spectre V2 : Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch
Spectre V2 : mitigation: Enabling conditional Indirect Branch Prediction Barrier
Speculative Store Bypass: Mitigation: Speculative Store Bypass disabled via prctl and seccomp
Freeing SMP alternatives memory: 40K
smpboot: CPU0: AMD GX-222GC SOC with Radeon(TM) R5E Graphics (family: 0x16, model: 0x30, stepping: 0x1)
Performance Events: AMD PMU driver.
... version:                0
... bit width:              48
... generic registers:      4
... value mask:             0000ffffffffffff
... max period:             00007fffffffffff
... fixed-purpose events:   0
... event mask:             000000000000000f
rcu: Hierarchical SRCU implementation.
dyndbg: Ignore empty _ddebug table in a CONFIG_DYNAMIC_DEBUG_CORE build
smp: Bringing up secondary CPUs ...
x86: Booting SMP configuration:
.... node  #0, CPUs:      #1
smp: Brought up 1 node, 2 CPUs
smpboot: Max logical packages: 2
smpboot: Total of 2 processors activated (8783.55 BogoMIPS)
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
futex hash table entries: 1024 (order: 4, 65536 bytes, linear)
pinctrl core: initialized pinctrl subsystem
NET: Registered protocol family 16
thermal_sys: Registered thermal governor 'step_wise'
thermal_sys: Registered thermal governor 'user_space'
cpuidle: using governor ladder
ACPI: bus type PCI registered
acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5
PCI: Using configuration type 1 for base access
PCI: Using configuration type 1 for extended access
cryptd: max_cpu_qlen set to 1000
ACPI: Added _OSI(Module Device)
ACPI: Added _OSI(Processor Device)
ACPI: Added _OSI(3.0 _SCP Extensions)
ACPI: Added _OSI(Processor Aggregator Device)
ACPI: Added _OSI(Linux-Dell-Video)
ACPI: Added _OSI(Linux-Lenovo-NV-HDMI-Audio)
ACPI: Added _OSI(Linux-HPI-Hybrid-Graphics)
ACPI: 6 ACPI AML tables successfully acquired and loaded
ACPI: Interpreter enabled
ACPI: (supports S0 S5)
ACPI: Using IOAPIC for interrupt routing
PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug
ACPI: Enabled 5 GPEs in block 00 to 1F
ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])
acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig Segments MSI HPX-Type3]
acpi PNP0A08:00: _OSC: not requesting OS control; OS requires [ExtendedConfig ASPM ClockPM MSI]
PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io  0x0000-0x03af window]
pci_bus 0000:00: root bus resource [io  0x03e0-0x0cf7 window]
pci_bus 0000:00: root bus resource [io  0x03b0-0x03df window]
pci_bus 0000:00: root bus resource [io  0x0d00-0xffff window]
pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff window]
pci_bus 0000:00: root bus resource [mem 0x000c0000-0x000dffff window]
pci_bus 0000:00: root bus resource [mem 0xf0000000-0xfed3ffff window]
pci_bus 0000:00: root bus resource [mem 0xfed45000-0xffffffff window]
pci_bus 0000:00: root bus resource [bus 00-ff]
pci 0000:00:00.0: [1022:1566] type 00 class 0x060000
pci 0000:00:01.0: [1002:9851] type 00 class 0x030000
pci 0000:00:01.0: reg 0x10: [mem 0xf8000000-0xfbffffff 64bit pref]
pci 0000:00:01.0: reg 0x18: [mem 0xfc000000-0xfc7fffff 64bit pref]
pci 0000:00:01.0: reg 0x20: [io  0xf000-0xf0ff]
pci 0000:00:01.0: reg 0x24: [mem 0xfeb00000-0xfeb3ffff]
pci 0000:00:01.0: reg 0x30: [mem 0xfeb40000-0xfeb5ffff pref]
pci 0000:00:01.0: enabling Extended Tags
pci 0000:00:01.0: supports D1 D2
pci 0000:00:01.0: PME# supported from D1 D2 D3hot
pci 0000:00:01.1: [1002:9840] type 00 class 0x040300
pci 0000:00:01.1: reg 0x10: [mem 0xfeb64000-0xfeb67fff 64bit]
pci 0000:00:01.1: enabling Extended Tags
pci 0000:00:01.1: supports D1 D2
pci 0000:00:02.0: [1022:156b] type 00 class 0x060000
pci 0000:00:02.1: [1022:1439] type 01 class 0x060400
pci 0000:00:02.1: enabling Extended Tags
pci 0000:00:02.1: PME# supported from D0 D3hot D3cold
pci 0000:00:02.2: [1022:1439] type 01 class 0x060400
pci 0000:00:02.2: enabling Extended Tags
pci 0000:00:02.2: PME# supported from D0 D3hot D3cold
pci 0000:00:08.0: [1022:1537] type 00 class 0x108000
pci 0000:00:08.0: reg 0x10: [mem 0xfc900000-0xfc91ffff 64bit pref]
pci 0000:00:08.0: reg 0x18: [mem 0xfe800000-0xfe8fffff]
pci 0000:00:08.0: reg 0x1c: [mem 0xfeb6f000-0xfeb6ffff]
pci 0000:00:08.0: reg 0x24: [mem 0xfeb6a000-0xfeb6bfff]
pci 0000:00:10.0: [1022:7814] type 00 class 0x0c0330
pci 0000:00:10.0: reg 0x10: [mem 0xfeb68000-0xfeb69fff 64bit]
pci 0000:00:10.0: PME# supported from D0 D3hot D3cold
pci 0000:00:11.0: [1022:7801] type 00 class 0x010601
pci 0000:00:11.0: reg 0x10: [io  0xf140-0xf147]
pci 0000:00:11.0: reg 0x14: [io  0xf130-0xf133]
pci 0000:00:11.0: reg 0x18: [io  0xf120-0xf127]
pci 0000:00:11.0: reg 0x1c: [io  0xf110-0xf113]
pci 0000:00:11.0: reg 0x20: [io  0xf100-0xf10f]
pci 0000:00:11.0: reg 0x24: [mem 0xfeb6e000-0xfeb6e3ff]
pci 0000:00:11.0: PME# supported from D3hot
pci 0000:00:12.0: [1022:7808] type 00 class 0x0c0320
pci 0000:00:12.0: reg 0x10: [mem 0xfeb6d000-0xfeb6d0ff]
pci 0000:00:12.0: supports D1 D2
pci 0000:00:12.0: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:13.0: [1022:7808] type 00 class 0x0c0320
pci 0000:00:13.0: reg 0x10: [mem 0xfeb6c000-0xfeb6c0ff]
pci 0000:00:13.0: supports D1 D2
pci 0000:00:13.0: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:14.0: [1022:780b] type 00 class 0x0c0500
pci 0000:00:14.2: [1022:780d] type 00 class 0x040300
pci 0000:00:14.2: reg 0x10: [mem 0xfeb60000-0xfeb63fff 64bit]
pci 0000:00:14.2: PME# supported from D0 D3hot D3cold
pci 0000:00:14.3: [1022:780e] type 00 class 0x060100
pci 0000:00:18.0: [1022:1580] type 00 class 0x060000
pci 0000:00:18.1: [1022:1581] type 00 class 0x060000
pci 0000:00:18.2: [1022:1582] type 00 class 0x060000
pci 0000:00:18.3: [1022:1583] type 00 class 0x060000
pci 0000:00:18.4: [1022:1584] type 00 class 0x060000
pci 0000:00:18.5: [1022:1585] type 00 class 0x060000
pci 0000:01:00.0: [10ec:8161] type 00 class 0x020000
pci 0000:01:00.0: reg 0x10: [io  0xe000-0xe0ff]
pci 0000:01:00.0: reg 0x18: [mem 0xfea04000-0xfea04fff 64bit]
pci 0000:01:00.0: reg 0x20: [mem 0xfea00000-0xfea03fff 64bit]
pci 0000:01:00.0: supports D1 D2
pci 0000:01:00.0: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:02.1: PCI bridge to [bus 01]
pci 0000:00:02.1:   bridge window [io  0xe000-0xefff]
pci 0000:00:02.1:   bridge window [mem 0xfea00000-0xfeafffff]
pci 0000:02:00.0: [10ec:8168] type 00 class 0x020000
pci 0000:02:00.0: reg 0x10: [io  0xd000-0xd0ff]
pci 0000:02:00.0: reg 0x18: [mem 0xfe900000-0xfe900fff 64bit]
pci 0000:02:00.0: reg 0x20: [mem 0xfc800000-0xfc803fff 64bit pref]
pci 0000:02:00.0: supports D1 D2
pci 0000:02:00.0: PME# supported from D0 D1 D2 D3hot D3cold
pci 0000:00:02.2: PCI bridge to [bus 02]
pci 0000:00:02.2:   bridge window [io  0xd000-0xdfff]
pci 0000:00:02.2:   bridge window [mem 0xfe900000-0xfe9fffff]
pci 0000:00:02.2:   bridge window [mem 0xfc800000-0xfc8fffff 64bit pref]
pci_bus 0000:00: on NUMA node 0
ACPI: PCI Interrupt Link [LNKA] (IRQs 4 *5 7 10 11 14 15)
ACPI: PCI Interrupt Link [LNKB] (IRQs 4 5 7 10 *11 14 15)
ACPI: PCI Interrupt Link [LNKC] (IRQs 4 5 7 *10 11 14 15)
ACPI: PCI Interrupt Link [LNKD] (IRQs 4 *5 7 10 11 14 15)
ACPI: PCI Interrupt Link [LNKE] (IRQs 4 5 7 10 *11 14 15)
ACPI: PCI Interrupt Link [LNKF] (IRQs 4 5 7 *10 11 14 15)
ACPI: PCI Interrupt Link [LNKG] (IRQs 4 5 7 10 11 14 15) *0
ACPI: PCI Interrupt Link [LNKH] (IRQs 4 5 7 10 11 14 15) *0
SCSI subsystem initialized
libata version 3.00 loaded.
ACPI: bus type USB registered
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
PCI: Using ACPI for IRQ routing
PCI: pci_cache_line_size set to 64 bytes
e820: reserve RAM buffer [mem 0x0009e800-0x0009ffff]
e820: reserve RAM buffer [mem 0xd98d3000-0xdbffffff]
e820: reserve RAM buffer [mem 0xdc1c8000-0xdfffffff]
e820: reserve RAM buffer [mem 0xdc339000-0xdfffffff]
e820: reserve RAM buffer [mem 0xdcc2d000-0xdfffffff]
e820: reserve RAM buffer [mem 0xdd000000-0xdfffffff]
e820: reserve RAM buffer [mem 0x11f000000-0x11fffffff]
hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0
hpet0: 3 comparators, 32-bit 14.318180 MHz counter
clocksource: Switched to clocksource tsc-early
pnp: PnP ACPI init
system 00:00: [mem 0xe0000000-0xefffffff] has been reserved
system 00:00: Plug and Play ACPI device, IDs PNP0c01 (active)
system 00:01: [mem 0xde000000-0xdfffffff] could not be reserved
system 00:01: Plug and Play ACPI device, IDs PNP0c02 (active)
system 00:02: Plug and Play ACPI device, IDs PNP0c02 (active)
pnp 00:03: [dma 0 disabled]
pnp 00:03: Plug and Play ACPI device, IDs PNP0501 (active)
system 00:04: [io  0x0640-0x064f] has been reserved
system 00:04: Plug and Play ACPI device, IDs PNP0c02 (active)
system 00:05: Plug and Play ACPI device, IDs PNP0c02 (active)
pnp 00:06: Plug and Play ACPI device, IDs PNP0b00 (active)
system 00:07: [io  0x04d0-0x04d1] has been reserved
system 00:07: Plug and Play ACPI device, IDs PNP0c02 (active)
pnp 00:08: [dma 0 disabled]
pnp 00:08: Plug and Play ACPI device, IDs PNP0501 (active)
system 00:09: [io  0x04d0-0x04d1] has been reserved
system 00:09: [io  0x040b] has been reserved
system 00:09: [io  0x04d6] has been reserved
system 00:09: [io  0x0c00-0x0c01] has been reserved
system 00:09: [io  0x0c14] has been reserved
system 00:09: [io  0x0c50-0x0c51] has been reserved
system 00:09: [io  0x0c52] has been reserved
system 00:09: [io  0x0c6c] has been reserved
system 00:09: [io  0x0c6f] has been reserved
system 00:09: [io  0x0cd0-0x0cd1] has been reserved
system 00:09: [io  0x0cd2-0x0cd3] has been reserved
system 00:09: [io  0x0cd4-0x0cd5] has been reserved
system 00:09: [io  0x0cd6-0x0cd7] has been reserved
system 00:09: [io  0x0cd8-0x0cdf] has been reserved
system 00:09: [io  0x0800-0x089f] has been reserved
system 00:09: [io  0x0b20-0x0b3f] has been reserved
system 00:09: [io  0x0900-0x090f] has been reserved
system 00:09: [io  0x0910-0x091f] has been reserved
system 00:09: [io  0xfe00-0xfefe] has been reserved
system 00:09: [mem 0xfec00000-0xfec00fff] could not be reserved
system 00:09: [mem 0xfee00000-0xfee00fff] has been reserved
system 00:09: [mem 0xfed80000-0xfed8ffff] has been reserved
system 00:09: [mem 0xfed61000-0xfed70fff] has been reserved
system 00:09: [mem 0xfed50000-0xfed50fff] has been reserved
system 00:09: [mem 0xff000000-0xffffffff] has been reserved
system 00:09: Plug and Play ACPI device, IDs PNP0c02 (active)
pnp: PnP ACPI: found 10 devices
clocksource: acpi_pm: mask: 0xffffff max_cycles: 0xffffff, max_idle_ns: 2085701024 ns
NET: Registered protocol family 2
IP idents hash table entries: 65536 (order: 7, 524288 bytes, linear)
tcp_listen_portaddr_hash hash table entries: 2048 (order: 3, 32768 bytes, linear)
TCP established hash table entries: 32768 (order: 6, 262144 bytes, linear)
TCP bind hash table entries: 32768 (order: 7, 524288 bytes, linear)
TCP: Hash tables configured (established 32768 bind 32768)
UDP hash table entries: 2048 (order: 4, 65536 bytes, linear)
UDP-Lite hash table entries: 2048 (order: 4, 65536 bytes, linear)
NET: Registered protocol family 1
pci 0000:00:02.1: PCI bridge to [bus 01]
pci 0000:00:02.1:   bridge window [io  0xe000-0xefff]
pci 0000:00:02.1:   bridge window [mem 0xfea00000-0xfeafffff]
pci 0000:00:02.2: PCI bridge to [bus 02]
pci 0000:00:02.2:   bridge window [io  0xd000-0xdfff]
pci 0000:00:02.2:   bridge window [mem 0xfe900000-0xfe9fffff]
pci 0000:00:02.2:   bridge window [mem 0xfc800000-0xfc8fffff 64bit pref]
pci_bus 0000:00: resource 4 [io  0x0000-0x03af window]
pci_bus 0000:00: resource 5 [io  0x03e0-0x0cf7 window]
pci_bus 0000:00: resource 6 [io  0x03b0-0x03df window]
pci_bus 0000:00: resource 7 [io  0x0d00-0xffff window]
pci_bus 0000:00: resource 8 [mem 0x000a0000-0x000bffff window]
pci_bus 0000:00: resource 9 [mem 0x000c0000-0x000dffff window]
pci_bus 0000:00: resource 10 [mem 0xf0000000-0xfed3ffff window]
pci_bus 0000:00: resource 11 [mem 0xfed45000-0xffffffff window]
pci_bus 0000:01: resource 0 [io  0xe000-0xefff]
pci_bus 0000:01: resource 1 [mem 0xfea00000-0xfeafffff]
pci_bus 0000:02: resource 0 [io  0xd000-0xdfff]
pci_bus 0000:02: resource 1 [mem 0xfe900000-0xfe9fffff]
pci_bus 0000:02: resource 2 [mem 0xfc800000-0xfc8fffff 64bit pref]
pci 0000:00:01.0: Video device with shadowed ROM at [mem 0x000c0000-0x000dffff]
pci 0000:00:01.1: D0 power state depends on 0000:00:01.0
pci 0000:00:12.0: PME# does not work under D3, disabling it
pci 0000:00:13.0: PME# does not work under D3, disabling it
PCI: CLS 64 bytes, default 64
PCI-DMA: Using software bounce buffering for IO (SWIOTLB)
software IO TLB: mapped [mem 0x00000000d58d3000-0x00000000d98d3000] (64MB)
amd_uncore: 4  amd_nb counters detected
amd_uncore: 4  amd_l2 counters detected
LVT offset 0 assigned for vector 0x400
perf: AMD IBS detected (0x000000ff)
workingset: timestamp_bits=46 max_order=20 bucket_order=0
squashfs: version 4.0 (2009/01/31) Phillip Lougher
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 249)
hv_vmbus: registering driver hyperv_fb
input: Power Button as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0C:00/input/input0
ACPI: Power Button [PWRB]
input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input1
ACPI: Power Button [PWRF]
ACPI: Video Device [VGA] (multi-head: yes  rom: no  post: no)
acpi device:01: registered as cooling_device0
input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/LNXVIDEO:00/input/input2
ACPI: Video Device [VGA1] (multi-head: yes  rom: no  post: no)
acpi device:34: registered as cooling_device1
input: Video Bus as /devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:33/LNXVIDEO:01/input/input3
ACPI: \_PR_.P000: Found 2 idle states
ACPI: \_PR_.P001: Found 2 idle states
Serial: 8250/16550 driver, 16 ports, IRQ sharing enabled
00:03: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
00:08: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A
Non-volatile memory driver v1.3
Linux agpgart interface v0.103
loop: module loaded
Guest personality initialized and is inactive
VMCI host device registered (name=vmci, major=10, minor=63)
Initialized host personality
Loading iSCSI transport class v2.0-870.
VMware PVSCSI driver - version 1.0.7.0-k
hv_vmbus: registering driver hv_storvsc
ahci 0000:00:11.0: version 3.0
ahci 0000:00:11.0: AHCI 0001.0300 32 slots 2 ports 6 Gbps 0x3 impl SATA mode
ahci 0000:00:11.0: flags: 64bit ncq sntf ilck led clo pmp pio slum part
scsi host0: ahci
scsi host1: ahci
ata1: SATA max UDMA/133 abar m1024@0xfeb6e000 port 0xfeb6e100 irq 28
ata2: SATA max UDMA/133 abar m1024@0xfeb6e000 port 0xfeb6e180 irq 28
VMware vmxnet3 virtual NIC driver - version 1.5.0.0-k-NAPI
hv_vmbus: registering driver hv_netvsc
Fusion MPT base driver 3.04.20
Copyright (c) 1999-2008 LSI Corporation
Fusion MPT SPI Host driver 3.04.20
Fusion MPT SAS Host driver 3.04.20
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
ehci-pci: EHCI PCI platform driver
ehci-pci 0000:00:12.0: EHCI Host Controller
ehci-pci 0000:00:12.0: new USB bus registered, assigned bus number 1
ehci-pci 0000:00:12.0: applying AMD SB700/SB800/Hudson-2/3 EHCI dummy qh workaround
ehci-pci 0000:00:12.0: debug port 2
ehci-pci 0000:00:12.0: irq 18, io mem 0xfeb6d000
ehci-pci 0000:00:12.0: USB 2.0 started, EHCI 1.00
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 2 ports detected
ehci-pci 0000:00:13.0: EHCI Host Controller
ehci-pci 0000:00:13.0: new USB bus registered, assigned bus number 2
ehci-pci 0000:00:13.0: applying AMD SB700/SB800/Hudson-2/3 EHCI dummy qh workaround
ehci-pci 0000:00:13.0: debug port 2
ehci-pci 0000:00:13.0: irq 18, io mem 0xfeb6c000
ehci-pci 0000:00:13.0: USB 2.0 started, EHCI 1.00
hub 2-0:1.0: USB hub found
hub 2-0:1.0: 2 ports detected
ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
ohci-pci: OHCI PCI platform driver
ohci-platform: OHCI generic platform driver
uhci_hcd: USB Universal Host Controller Interface driver
xhci_hcd 0000:00:10.0: xHCI Host Controller
xhci_hcd 0000:00:10.0: new USB bus registered, assigned bus number 3
xhci_hcd 0000:00:10.0: hcc params 0x014040c3 hci version 0x100 quirks 0x0000000000000410
hub 3-0:1.0: USB hub found
hub 3-0:1.0: 2 ports detected
xhci_hcd 0000:00:10.0: xHCI Host Controller
xhci_hcd 0000:00:10.0: new USB bus registered, assigned bus number 4
xhci_hcd 0000:00:10.0: Host supports USB 3.0 SuperSpeed
usb usb4: We don't know the algorithms for LPM for this host, disabling LPM.
hub 4-0:1.0: USB hub found
hub 4-0:1.0: 2 ports detected
usbcore: registered new interface driver usb-storage
i8042: PNP: No PS/2 controller found.
hv_vmbus: registering driver hyperv_keyboard
rtc_cmos 00:06: RTC can wake from S4
rtc_cmos 00:06: registered as rtc0
rtc_cmos 00:06: setting system clock to 2022-10-18T06:12:15 UTC (1666073535)
rtc_cmos 00:06: alarms up to one month, y3k, 114 bytes nvram, hpet irqs
sdhci: Secure Digital Host Controller Interface driver
sdhci: Copyright(c) Pierre Ossman
hid: raw HID events driver (C) Jiri Kosina
ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
hv_vmbus: registering driver hid_hyperv
ata1: SATA link down (SStatus 0 SControl 300)
usbcore: registered new interface driver usbhid
ata2.00: ATA-8: Innodisk DEMSR- 08GB mSATA 3ME3, S16425G3, max UDMA/133
usbhid: USB HID core driver
ata2.00: 15622144 sectors, multi 1: LBA48 NCQ (depth 32), AA
hv_utils: Registering HyperV Utility Driver
ata2.00: configured for UDMA/133
hv_vmbus: registering driver hv_utils
scsi 1:0:0:0: Direct-Access     ATA      Innodisk DEMSR-  25G3 PQ: 0 ANSI: 5
hv_vmbus: registering driver hv_balloon
sd 1:0:0:0: [sda] 15622144 512-byte logical blocks: (8.00 GB/7.45 GiB)
NET: Registered protocol family 10
sd 1:0:0:0: [sda] Write Protect is off
Segment Routing with IPv6
sd 1:0:0:0: [sda] Mode Sense: 00 3a 00 00
NET: Registered protocol family 17
sd 1:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
 sda: sda1 sda2
8021q: 802.1Q VLAN Support v1.8
NET: Registered protocol family 40
sd 1:0:0:0: [sda] Attached SCSI disk
x86/pm: family 0x16 cpu detected, MSR saving is needed during suspending.
microcode: CPU0: patch_level=0x07030106
microcode: CPU1: patch_level=0x07030106
usb 1-1: new high-speed USB device number 2 using ehci-pci
microcode: Microcode Update Driver: v2.2.
IPI shorthand broadcast: enabled
AVX version of gcm_enc/dec engaged.
AES CTR mode by8 optimization enabled
usb 2-1: new high-speed USB device number 2 using ehci-pci
sched_clock: Marking stable (2579137342, 865861756)->(3460805851, -15806753)
registered taskstats version 1
acpi_cpufreq: overriding BIOS provided _PSD data
EXT4-fs (sda2): mounted filesystem without journal. Opts: (null)
VFS: Mounted root (ext4 filesystem) readonly on device 8:2.
Freeing unused kernel image (initmem) memory: 1164K
Write protecting the kernel read-only data: 18432k
Freeing unused kernel image (text/rodata gap) memory: 2044K
Freeing unused kernel image (rodata/data gap) memory: 2032K
Run /sbin/init as init process
  with arguments:
    /sbin/init
  with environment:
    HOME=/
    TERM=linux
    BOOT_IMAGE=/boot/vmlinuz
init: Console is alive
kmodloader: loading kernel modules from /etc/modules-boot.d/*
hub 1-1:1.0: USB hub found
hub 1-1:1.0: 4 ports detected
pps_core: LinuxPPS API ver. 1 registered
pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
hub 2-1:1.0: USB hub found
hub 2-1:1.0: 4 ports detected
PTP clock support registered
Button Hotplug driver version 0.4.1
igb: Intel(R) Gigabit Ethernet Network Driver
igb: Copyright (c) 2007-2014 Intel Corporation.
kmodloader: done loading kernel modules from /etc/modules-boot.d/*
init: - preinit -
tsc: Refined TSC clocksource calibration: 2195.881 MHz
clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x1fa6ffc1640, max_idle_ns: 440795239502 ns
clocksource: Switched to clocksource tsc
random: jshn: uninitialized urandom read (4 bytes read)
random: jshn: uninitialized urandom read (4 bytes read)
random: jshn: uninitialized urandom read (4 bytes read)
mount_root: mounting /dev/root
EXT4-fs (sda2): warning: mounting unchecked fs, running e2fsck is recommended
EXT4-fs (sda2): re-mounted. Opts: (null)
EXT4-fs (sda1): warning: mounting unchecked fs, running e2fsck is recommended
EXT4-fs (sda1): mounted filesystem without journal. Opts: (null)
urandom-seed: Seeding with /etc/urandom.seed
procd: - early -
procd: - ubus -
random: ubusd: uninitialized urandom read (4 bytes read)
random: ubusd: uninitialized urandom read (4 bytes read)
random: ubusd: uninitialized urandom read (4 bytes read)
procd: - init -
urngd: v1.0.2 started.
kmodloader: loading kernel modules from /etc/modules.d/*
random: crng init done
random: 21 urandom warning(s) missed due to ratelimiting
e1000: Intel(R) PRO/1000 Network Driver
e1000: Copyright (c) 1999-2006 Intel Corporation.
ixgbe: Intel(R) 10 Gigabit PCI Express Network Driver
ixgbe: Copyright (c) 1999-2016 Intel Corporation.
i2c /dev entries driver
e1000e: Intel(R) PRO/1000 Network Driver
e1000e: Copyright(c) 1999 - 2015 Intel Corporation.
Intel(R) 2.5G Ethernet Linux Driver
Copyright(c) 2018 Intel Corporation.
usbcore: registered new interface driver r8152
r8169 0000:01:00.0 eth0: RTL8168h/8111h, xx:xx:xx:xx:xx:xx, XID 541, IRQ 32
r8169 0000:01:00.0 eth0: jumbo features [frames: 9194 bytes, tx checksumming: ko]
r8169 0000:02:00.0 eth1: RTL8168g/8111g, yy:yy:yy:yy:yy:yy, XID 4c0, IRQ 34
r8169 0000:02:00.0 eth1: jumbo features [frames: 9194 bytes, tx checksumming: ko]
xt_time: kernel timezone is -0000
usbcore: registered new interface driver cdc_ether
usbcore: registered new interface driver cdc_ncm
PPP generic driver version 2.4.2
NET: Registered protocol family 24
kmodloader: done loading kernel modules from /etc/modules.d/*
Generic FE-GE Realtek PHY r8169-0-200:00: attached PHY driver [Generic FE-GE Realtek PHY] (mii_bus:phy_addr=r8169-0-200:00, irq=IGNORE)
br-lan: port 1(eth1) entered blocking state
br-lan: port 1(eth1) entered disabled state
device eth1 entered promiscuous mode
r8169 0000:02:00.0 eth1: Link is Down
br-lan: port 1(eth1) entered blocking state
br-lan: port 1(eth1) entered forwarding state
Generic FE-GE Realtek PHY r8169-0-100:00: attached PHY driver [Generic FE-GE Realtek PHY] (mii_bus:phy_addr=r8169-0-100:00, irq=IGNORE)
r8169 0000:01:00.0 eth0: Link is Down
br-lan: port 1(eth1) entered disabled state
r8169 0000:01:00.0 eth0: Link is Up - 1Gbps/Full - flow control off
IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
pppoe-wan: renamed from ppp0
r8169 0000:02:00.0 eth1: Link is Up - 1Gbps/Full - flow control rx/tx
br-lan: port 1(eth1) entered blocking state
br-lan: port 1(eth1) entered forwarding state

a bandwidth test on a different site reveals 100Mbit/sec uplink after the slowdown happens.
One might think that the network card switched from 1Gbit/sec to 100Mbit/sec.
Anyone experiencing something similar ?

what does dmesg say ?

dmesg output in the first post, nothing that could indicate the problem, in my opinion.

And if you try to force the link using ethtool?

root@OpenWrt:~# cat /sys/class/net/eth0/speed /sys/class/net/eth0/duplex
1000
full
root@OpenWrt:~# cat /sys/class/net/eth1/speed /sys/class/net/eth1/duplex
1000
full

looks like full speed 1g on both

root@OpenWrt:~# mii-tool eth0
eth0: negotiated 1000baseT-FD flow-control, link ok
root@OpenWrt:~# mii-tool eth1
eth1: negotiated 1000baseT-FD flow-control, link ok

Did You tried pfsense? I have faster one model with quad core and intel x520 and it works fine. Also i have diderent cards, had problem with cheap marvel 1 port cards, may find time to plat with mine layter today - i have ten if them now.