Low wired speed with Xiaomi AIOT AC2350 on 23.05

Hello, I just installed 23.05 on Xiaomi Aiot AC2350 and I found out the wired network speed maxes out at around 200-250 Mbits/s.
The device was used as a dump access point but for diagnostic purpose I resetted it to defaults and tested it with iperf3 and got this results:

root@OpenWrt:~# iperf3 -s
-----------------------------------------------------------
Server listening on 5201 (test #1)
-----------------------------------------------------------
Accepted connection from 192.168.1.149, port 64984
[  5] local 192.168.1.1 port 5201 connected to 192.168.1.149 port 64985
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  33.4 MBytes   279 Mbits/sec
[  5]   1.00-2.01   sec  34.0 MBytes   284 Mbits/sec
[  5]   2.01-3.01   sec  34.0 MBytes   286 Mbits/sec
[  5]   3.01-4.00   sec  34.0 MBytes   286 Mbits/sec
[  5]   4.00-5.00   sec  31.6 MBytes   265 Mbits/sec
[  5]   5.00-6.01   sec  34.2 MBytes   286 Mbits/sec
[  5]   6.01-7.00   sec  31.8 MBytes   267 Mbits/sec
[  5]   7.00-8.01   sec  34.0 MBytes   284 Mbits/sec
[  5]   8.01-9.00   sec  34.1 MBytes   287 Mbits/sec
[  5]   9.00-10.00  sec  34.0 MBytes   286 Mbits/sec
[  5]  10.00-10.01  sec   256 KBytes   164 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.01  sec   335 MBytes   281 Mbits/sec                  receiver
-----------------------------------------------------------
Server listening on 5201 (test #2)
-----------------------------------------------------------
Accepted connection from 192.168.1.149, port 64986
[  5] local 192.168.1.1 port 5201 connected to 192.168.1.149 port 64987
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.06   sec  28.8 MBytes   228 Mbits/sec    0    268 KBytes
[  5]   1.06-2.07   sec  27.5 MBytes   228 Mbits/sec    0    268 KBytes
[  5]   2.07-3.09   sec  27.5 MBytes   226 Mbits/sec    0    268 KBytes
[  5]   3.09-4.05   sec  26.0 MBytes   228 Mbits/sec    0    268 KBytes
[  5]   4.05-5.07   sec  27.5 MBytes   226 Mbits/sec    0    268 KBytes
[  5]   5.07-6.09   sec  27.6 MBytes   226 Mbits/sec    0    268 KBytes
[  5]   6.09-7.06   sec  26.2 MBytes   227 Mbits/sec    0    268 KBytes
[  5]   7.06-8.07   sec  27.5 MBytes   228 Mbits/sec    0    268 KBytes
[  5]   8.07-9.08   sec  27.5 MBytes   228 Mbits/sec    0    268 KBytes
[  5]   9.08-10.05  sec  26.2 MBytes   228 Mbits/sec    0    268 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.05  sec   272 MBytes   227 Mbits/sec    0             sender

Only errors in the system log are these, not sure if they have any significance for the issue:

Mon Oct  9 21:47:42 2023 kern.err kernel: [    0.367665] OF: Bad cell count for /ahb/spi@1f000000/flash@0/partitions
Mon Oct  9 21:47:42 2023 kern.err kernel: [    0.374529] OF: Bad cell count for /ahb/spi@1f000000/flash@0/partitions
Mon Oct  9 21:47:42 2023 kern.err kernel: [    0.381812] OF: Bad cell count for /ahb/spi@1f000000/flash@0/partitions
Mon Oct  9 21:47:42 2023 kern.err kernel: [    0.388736] OF: Bad cell count for /ahb/spi@1f000000/flash@0/partitions
Mon Oct  9 21:47:42 2023 kern.err kernel: [   18.763256] ath10k_pci 0000:00:00.0: failed to fetch board data for bus=pci,bmi-chip-id=0,bmi-board-id=16 from ath10k/QCA9984/hw1.0/board-2.bin
Mon Oct  9 21:47:59 2023 daemon.err odhcp6c[2060]: Failed to send RS (Address not available)
Mon Oct  9 21:47:59 2023 daemon.err odhcp6c[2060]: Failed to send SOLICIT message to ff02::1:2 (Address not available)
Mon Oct  9 21:48:04 2023 daemon.warn odhcpd[1524]: No default route present, overriding ra_lifetime!
Thu Nov  2 09:32:13 2023 daemon.warn odhcpd[1524]: No default route present, overriding ra_lifetime!
Thu Nov  2 09:32:29 2023 daemon.warn odhcpd[1524]: No default route present, overriding ra_lifetime!
Thu Nov  2 09:32:36 2023 daemon.err uhttpd[1642]: [info] luci: accepted login on / for root from 192.168.1.149
Thu Nov  2 09:36:37 2023 daemon.warn odhcpd[1524]: No default route present, overriding ra_lifetime!

EDIT: I did a longer iperf test and I notice the systems loads climbs up all the way to 1.0 in 2-3 mins:

Any clue whats could be causing this low speed?