Intel 8260 card won't use VHT/ac mode

I've a laptop with the Intel 8260 card (running Manjaro stable) which according to the spec should support ac mode connection. The router in use is Xiaomi 3G v1 with 2.4GHz radio disabled running openwrt v22.03.3. A Samsung phone connects to it in ac mode, luci displays "866.7 Mbit/s, 80 MHz, VHT-MCS 9, VHT-NSS 2, Short GI". But for the laptop it's "300.0 Mbit/s, 40 MHz, MCS 15, Short GI".
The relevant messages in the system log:

[ 5993.400415] wlp4s0: 80 MHz not supported, disabling VHT
[ 5993.400429] wlp4s0: capabilities/regulatory prevented using AP HT/VHT configuration, downgraded
iw phy:
Wiphy phy0
        wiphy index: 0
        max # scan SSIDs: 20
        max scan IEs length: 422 bytes
        max # sched scan SSIDs: 20
        max # match sets: 11
        Retry short limit: 7
        Retry long limit: 4
        Coverage class: 0 (up to 0m)
        Device supports RSN-IBSS.
        Device supports AP-side u-APSD.
        Supported Ciphers:
                * WEP40 (00-0f-ac:1)
                * WEP104 (00-0f-ac:5)
                * TKIP (00-0f-ac:2)
                * CCMP-128 (00-0f-ac:4)
                * CMAC (00-0f-ac:6)
        Available Antennas: TX 0x3 RX 0x3
        Configured Antennas: TX 0x3 RX 0x3
        Supported interface modes:
                 * IBSS
                 * managed
                 * AP
                 * AP/VLAN
                 * monitor
                 * P2P-client
                 * P2P-GO
                 * P2P-device
        Band 1:
                Capabilities: 0x11ef
                        RX LDPC
                        HT20/HT40
                        SM Power Save disabled
                        RX HT20 SGI
                        RX HT40 SGI
                        TX STBC
                        RX STBC 1-stream
                        Max AMSDU length: 3839 bytes
                        DSSS/CCK HT40
                Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
                Minimum RX AMPDU time spacing: 4 usec (0x05)
                HT Max RX data rate: 300 Mbps
                HT TX/RX MCS rate indexes supported: 0-15
                Bitrates (non-HT):
                        * 1.0 Mbps
                        * 2.0 Mbps (short preamble supported)
                        * 5.5 Mbps (short preamble supported)
                        * 11.0 Mbps (short preamble supported)
                        * 6.0 Mbps
                        * 9.0 Mbps
                        * 12.0 Mbps
                        * 18.0 Mbps
                        * 24.0 Mbps
                        * 36.0 Mbps
                        * 48.0 Mbps
                        * 54.0 Mbps
                Frequencies:
                        * 2412 MHz [1] (22.0 dBm)
                        * 2417 MHz [2] (22.0 dBm)
                        * 2422 MHz [3] (22.0 dBm)
                        * 2427 MHz [4] (22.0 dBm)
                        * 2432 MHz [5] (22.0 dBm)
                        * 2437 MHz [6] (22.0 dBm)
                        * 2442 MHz [7] (22.0 dBm)
                        * 2447 MHz [8] (22.0 dBm)
                        * 2452 MHz [9] (22.0 dBm)
                        * 2457 MHz [10] (22.0 dBm)
                        * 2462 MHz [11] (22.0 dBm)
                        * 2467 MHz [12] (22.0 dBm)
                        * 2472 MHz [13] (22.0 dBm)
                        * 2484 MHz [14] (disabled)
        Band 2:
                Capabilities: 0x11ef
                        RX LDPC
                        HT20/HT40
                        SM Power Save disabled
                        RX HT20 SGI
                        RX HT40 SGI
                        TX STBC
                        RX STBC 1-stream
                        Max AMSDU length: 3839 bytes
                        DSSS/CCK HT40
                Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
                Minimum RX AMPDU time spacing: 4 usec (0x05)
                HT Max RX data rate: 300 Mbps
                HT TX/RX MCS rate indexes supported: 0-15
                VHT Capabilities (0x038071b0):
                        Max MPDU length: 3895
                        Supported Channel Width: neither 160 nor 80+80
                        RX LDPC
                        short GI (80 MHz)
                        TX STBC
                        SU Beamformee
                VHT RX MCS set:
                        1 streams: MCS 0-9
                        2 streams: MCS 0-9
                        3 streams: not supported
                        4 streams: not supported
                        5 streams: not supported
                        6 streams: not supported
                        7 streams: not supported
                        8 streams: not supported
                VHT RX highest supported: 0 Mbps
                VHT TX MCS set:
                        1 streams: MCS 0-9
                        2 streams: MCS 0-9
                        3 streams: not supported
                        4 streams: not supported
                        5 streams: not supported
                        6 streams: not supported
                        7 streams: not supported
                        8 streams: not supported
                VHT TX highest supported: 0 Mbps
                VHT extended NSS: supported
                Bitrates (non-HT):
                        * 6.0 Mbps
                        * 9.0 Mbps
                        * 12.0 Mbps
                        * 18.0 Mbps
                        * 24.0 Mbps
                        * 36.0 Mbps
                        * 48.0 Mbps
                        * 54.0 Mbps
                Frequencies:
                        * 5180 MHz [36] (22.0 dBm) (no IR)
                        * 5200 MHz [40] (22.0 dBm) (no IR)
                        * 5220 MHz [44] (22.0 dBm) (no IR)
                        * 5240 MHz [48] (22.0 dBm) (no IR)
                        * 5260 MHz [52] (22.0 dBm) (no IR, radar detection)
                        * 5280 MHz [56] (22.0 dBm) (no IR, radar detection)
                        * 5300 MHz [60] (22.0 dBm) (no IR, radar detection)
                        * 5320 MHz [64] (22.0 dBm) (no IR, radar detection)
                        * 5340 MHz [68] (disabled)
                        * 5360 MHz [72] (disabled)
                        * 5380 MHz [76] (disabled)
                        * 5400 MHz [80] (disabled)
                        * 5420 MHz [84] (disabled)
                        * 5440 MHz [88] (disabled)
                        * 5460 MHz [92] (disabled)
                        * 5480 MHz [96] (disabled)
                        * 5500 MHz [100] (22.0 dBm) (no IR, radar detection)
                        * 5520 MHz [104] (22.0 dBm) (no IR, radar detection)
                        * 5540 MHz [108] (22.0 dBm) (no IR, radar detection)
                        * 5560 MHz [112] (22.0 dBm) (no IR, radar detection)
                        * 5580 MHz [116] (22.0 dBm) (no IR, radar detection)
                        * 5600 MHz [120] (22.0 dBm) (no IR, radar detection)
                        * 5620 MHz [124] (22.0 dBm) (no IR, radar detection)
                        * 5640 MHz [128] (22.0 dBm) (no IR, radar detection)
                        * 5660 MHz [132] (22.0 dBm) (no IR, radar detection)
                        * 5680 MHz [136] (22.0 dBm) (no IR, radar detection)
                        * 5700 MHz [140] (22.0 dBm) (no IR, radar detection)
                        * 5720 MHz [144] (22.0 dBm) (no IR, radar detection)
                        * 5745 MHz [149] (22.0 dBm)
                        * 5765 MHz [153] (22.0 dBm)
                        * 5785 MHz [157] (22.0 dBm)
                        * 5805 MHz [161] (22.0 dBm)
                        * 5825 MHz [165] (22.0 dBm)
                        * 5845 MHz [169] (disabled)
                        * 5865 MHz [173] (disabled)
                        * 5885 MHz [177] (disabled)
                        * 5905 MHz [181] (disabled)
        Supported commands:
                 * new_interface
                 * set_interface
                 * new_key
                 * start_ap
                 * new_station
                 * new_mpath
                 * set_mesh_config
                 * set_bss
                 * authenticate
                 * associate
                 * deauthenticate
                 * disassociate
                 * join_ibss
                 * join_mesh
                 * remain_on_channel
                 * set_tx_bitrate_mask
                 * frame
                 * frame_wait_cancel
                 * set_wiphy_netns
                 * set_channel
                 * start_sched_scan
                 * probe_client
                 * set_noack_map
                 * register_beacons
                 * start_p2p_device
                 * set_mcast_rate
                 * connect
                 * disconnect
                 * channel_switch
                 * set_qos_map
                 * add_tx_ts
                 * set_multicast_to_unicast
        WoWLAN support:
                 * wake up on disconnect
                 * wake up on magic packet
                 * wake up on pattern match, up to 20 patterns of 16-128 bytes,
                   maximum packet offset 0 bytes
                 * can do GTK rekeying
                 * wake up on GTK rekey failure
                 * wake up on EAP identity request
                 * wake up on 4-way handshake
                 * wake up on rfkill release
                 * wake up on network detection, up to 11 match sets
        software interface modes (can always be added):
                 * AP/VLAN
                 * monitor
        valid interface combinations:
                 * #{ managed } <= 1, #{ AP, P2P-client, P2P-GO } <= 1, #{ P2P-device } <= 1,
                   total <= 3, #channels <= 2
        HT Capability overrides:
                 * MCS: ff ff ff ff ff ff ff ff ff ff
                 * maximum A-MSDU length
                 * supported channel width
                 * short GI for 40 MHz
                 * max A-MPDU length exponent
                 * min MPDU start spacing
        Device supports TX status socket option.
        Device supports HT-IBSS.
        Device supports SAE with AUTHENTICATE command
        Device supports low priority scan.
        Device supports scan flush.
        Device supports per-vif TX power setting
        P2P GO supports CT window setting
        P2P GO supports opportunistic powersave setting
        Driver supports full state transitions for AP/GO clients
        Driver supports a userspace MPM
        Driver/device bandwidth changes during BSS lifetime (AP/GO mode)
        Device adds DS IE to probe requests
        Device can update TPC Report IE
        Device supports static SMPS
        Device supports dynamic SMPS
        Device supports WMM-AC admission (TSPECs)
        Device supports configuring vdev MAC-addr on create.
        Device supports randomizing MAC-addr in scans.
        Device supports randomizing MAC-addr in sched scans.
        Device supports randomizing MAC-addr in net-detect scans.
        max # scan plans: 2
        max scan plan interval: 65535
        max scan plan iterations: 254
        Supported TX frame types:
                 * IBSS: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
                 * managed: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
                 * AP: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
                 * AP/VLAN: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
                 * mesh point: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
                 * P2P-client: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
                 * P2P-GO: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
                 * P2P-device: 0x00 0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80 0x90 0xa0 0xb0 0xc0 0xd0 0xe0 0xf0
        Supported RX frame types:
                 * IBSS: 0x40 0xb0 0xc0 0xd0
                 * managed: 0x40 0xb0 0xd0
                 * AP: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
                 * AP/VLAN: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
                 * mesh point: 0xb0 0xc0 0xd0
                 * P2P-client: 0x40 0xd0
                 * P2P-GO: 0x00 0x20 0x40 0xa0 0xb0 0xc0 0xd0
                 * P2P-device: 0x40 0xd0
        Supported extended features:
                * [ VHT_IBSS ]: VHT-IBSS
                * [ RRM ]: RRM
                * [ SCAN_START_TIME ]: scan start timestamp
                * [ BSS_PARENT_TSF ]: BSS last beacon/probe TSF
                * [ BEACON_RATE_LEGACY ]: legacy beacon rate setting
                * [ FILS_STA ]: STA FILS (Fast Initial Link Setup)
                * [ FILS_MAX_CHANNEL_TIME ]: FILS max channel attribute override with dwell time
                * [ ACCEPT_BCAST_PROBE_RESP ]: accepts broadcast probe response
                * [ OCE_PROBE_REQ_HIGH_TX_RATE ]: probe request TX at high rate (at least 5.5Mbps)
                * [ OCE_PROBE_REQ_DEFERRAL_SUPPRESSION ]: probe request tx deferral and suppression
                * [ CONTROL_PORT_OVER_NL80211 ]: control port over nl80211
                * [ TXQS ]: FQ-CoDel-enabled intermediate TXQs
                * [ EXT_KEY_ID ]: Extended Key ID support
                * [ CONTROL_PORT_NO_PREAUTH ]: disable pre-auth over nl80211 control port support
                * [ DEL_IBSS_STA ]: deletion of IBSS station support
                * [ SCAN_FREQ_KHZ ]: scan on kHz frequency support
                * [ CONTROL_PORT_OVER_NL80211_TX_STATUS ]: tx status for nl80211 control port support

if you're running Manjaro, how is this related to openwrt ?

I'm not sure where the problem lies, the router's configuration or the card's.

I've moved with the laptop around the room and after a suspend/resume it connected in VHT mode without a hitch. Related to the signal's power I guess?

If you're expecting to see the same thing displayed 100% of the time, it won't.

Yeah, after some time it's again stuck in n mode. Is there something I can tweak to affect this? I don't understand where and why this happens.

Any chance you can swap in another router or AP to test? And revert your Xiaomi to an older release (or master) to see whether your client behaves better.

Maybe it's DFS channel limitations?

Please copy the output of the following commands and post it here using the "Preformatted text </> " button.

Remember to redact passwords, MAC addresses and any public IP addresses you may have:

cat /etc/config/network
cat /etc/config/wireless
cat /etc/config/dhcp
cat /etc/config/firewall

Alternatively:

ubus call system board; \
uci export network; uci export wireless; \
uci export dhcp; uci export firewall

Then the smartphone wouldn't be operating on 80 MHz.

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After some digging it seems the problem is in the intel firmware, the regulatory information it contains is either out of date or plain wrong, but it doesn't correspond to the real world data. Most of the times the firmware guesses the country right, but due to the aforementioned problem limits itself to 40MHz width. And sometimes it guesses (or falls back?) wrong and is able to utilize the full width due to correctly set limits. And since Linux 5.4 you can't override it manually with out-of-the-box kernels. I don't see any trivial solution or workaround for myself other than turning wifi off and on again a few times hoping that it guesses wrong.

firmware guesses right, but its regulatory data is incorrect:
phy#0 (self-managed)
country RU: DFS-UNSET
        (2402 - 2437 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ
        (2422 - 2462 @ 40), (6, 22), (N/A), AUTO-BW, NO-80MHZ, NO-160MHZ
        (2447 - 2482 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ
        (5170 - 5190 @ 40), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5190 - 5210 @ 40), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5210 - 5230 @ 40), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5230 - 5250 @ 40), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5250 - 5270 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5270 - 5290 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5290 - 5310 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5310 - 5330 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5490 - 5510 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5510 - 5530 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5530 - 5550 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5550 - 5570 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5570 - 5590 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5590 - 5610 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5610 - 5630 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5630 - 5650 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5650 - 5670 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5670 - 5690 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5690 - 5710 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5710 - 5730 @ 40), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
        (5735 - 5755 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ
        (5755 - 5775 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ
        (5775 - 5795 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ
        (5795 - 5815 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ
        (5815 - 5835 @ 20), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-HT40PLUS, NO-80MHZ, NO-160MHZ

correct data from https://git.kernel.org/pub/scm/linux/kernel/git/sforshee/wireless-regdb.git/tree/db.txt
country RU: DFS-ETSI
	(2400 - 2483.5 @ 40), (20)
	(5150 - 5350 @ 160), (100 mW), NO-OUTDOOR, DFS
	(5650 - 5850 @ 160), (100 mW), NO-OUTDOOR, DFS
firmware guesses wrong, but at least width limits here are correct
phy#0 (self-managed)
country CN: DFS-UNSET
        (2402 - 2437 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40MINUS, NO-80MHZ, NO-160MHZ
        (2422 - 2462 @ 40), (6, 22), (N/A), AUTO-BW, NO-80MHZ, NO-160MHZ
        (2447 - 2482 @ 40), (6, 22), (N/A), AUTO-BW, NO-HT40PLUS, NO-80MHZ, NO-160MHZ
        (5170 - 5190 @ 80), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5190 - 5210 @ 80), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5210 - 5230 @ 80), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5230 - 5250 @ 80), (6, 22), (N/A), NO-OUTDOOR, AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5250 - 5270 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5270 - 5290 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5290 - 5310 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5310 - 5330 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5490 - 5510 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5510 - 5530 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5530 - 5550 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5550 - 5570 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5570 - 5590 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5590 - 5610 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5610 - 5630 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5630 - 5650 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5650 - 5670 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5670 - 5690 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5690 - 5710 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5710 - 5730 @ 80), (6, 22), (0 ms), DFS, AUTO-BW, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5735 - 5755 @ 80), (6, 22), (N/A), AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5755 - 5775 @ 80), (6, 22), (N/A), AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5775 - 5795 @ 80), (6, 22), (N/A), AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-160MHZ, PASSIVE-SCAN
        (5795 - 5815 @ 80), (6, 22), (N/A), AUTO-BW, IR-CONCURRENT, NO-HT40PLUS, NO-160MHZ, PASSIVE-SCAN
        (5815 - 5835 @ 20), (6, 22), (N/A), AUTO-BW, IR-CONCURRENT, NO-HT40MINUS, NO-HT40PLUS, NO-80MHZ, NO-160MHZ, PASSIVE-SCAN
reference data, ibid.:
country CN: DFS-FCC
	(2400 - 2483.5 @ 40), (20)
	(5150 - 5350 @ 80), (20), DFS, AUTO-BW
	(5725 - 5850 @ 80), (33)

There is a number of issues related to the problem on kernel's bug tracker, here are some for reference:
https://bugzilla.kernel.org/show_bug.cgi?id=205695
https://bugzilla.kernel.org/show_bug.cgi?id=208071
https://bugzilla.kernel.org/show_bug.cgi?id=206469

2 Likes

Sometimes it could be Linux driver issue, my mini PC has Atheros QCA9377 which is 1x1 AC wifi, but under Linux it always shows "6Mbps" even router side is reporting 433Mbps, I just ignore it.

If you have Windows try to boot into it, most likely your Windows driver can give proper numbers.

I rarely use the preinstalled Windows, but I've checked how things are there recently and it used ac mode throughout the session. But according to threads like this https://community.intel.com/t5/Intel-NUCs/Wireless-AC-8265-AX-200-sets-the-incorrect-regulatory-domain/td-p/734887 the LAR mechanism is used there too, and if the problem occurs you are completely out of options.

1 Like