Redmi AX6000 lost 5 GHz radio

Has anyone with the Redmi AX6000 or with the MT7986A SoC experienced the 5 GHz SSIDs just disappear? It's looking like the DFS detected some weather radar or something and it never recovered. Why did the bridge br-lan get deleted?

I am running a snapshot built on 30-Mar-2023. The last-known-good build was from from about 1 week prior.

logread
Fri Mar 31 00:51:31 2023 daemon.notice hostapd: phy1-ap0: DFS-RADAR-DETECTED freq=5500 ht_enabled=0 chan_offset=0 chan_width=5 cf1=5570 cf2=0
Fri Mar 31 00:51:31 2023 daemon.notice hostapd: dfs_downgrade_bandwidth: no DFS channels left, waiting for NOP to finish
Fri Mar 31 00:51:31 2023 daemon.notice hostapd: phy1-ap0: AP-DISABLED
Fri Mar 31 00:51:31 2023 daemon.notice hostapd: phy1-ap0: AP-STA-DISCONNECTED xx:xx:xx:xx:xx:xx
Fri Mar 31 00:51:31 2023 daemon.notice hostapd: phy1-ap0: AP-STA-DISCONNECTED xx:xx:xx:xx:xx:xx
Fri Mar 31 00:51:31 2023 daemon.notice hostapd: phy1-ap0: AP-STA-DISCONNECTED xx:xx:xx:xx:xx:xx
Fri Mar 31 00:51:31 2023 daemon.err hostapd: 20/40 MHz: center segment 0 (=114) and center freq 1 (=5510) not in sync
Fri Mar 31 00:51:31 2023 daemon.err hostapd: 20/40 MHz: center segment 0 (=114) and center freq 1 (=5510) not in sync
Fri Mar 31 00:51:31 2023 daemon.err hostapd: 20/40 MHz: center segment 0 (=114) and center freq 1 (=5510) not in sync
Fri Mar 31 00:51:31 2023 daemon.err hostapd: 20/40 MHz: center segment 0 (=114) and center freq 1 (=5510) not in sync
Fri Mar 31 00:51:31 2023 daemon.notice netifd: Network device 'phy1-ap1' link is down
Fri Mar 31 00:51:31 2023 kern.info kernel: [53536.746182] br-lan: port 6(phy1-ap1) entered disabled state
Fri Mar 31 00:51:32 2023 kern.info kernel: [53536.805666] device phy1-ap1 left promiscuous mode
Fri Mar 31 00:51:32 2023 kern.info kernel: [53536.810629] br-lan: port 6(phy1-ap1) entered disabled state
Fri Mar 31 00:51:32 2023 daemon.notice netifd: lan (2328): udhcpc: sending renew to server 10.9.8.1
Fri Mar 31 00:51:32 2023 daemon.notice netifd: lan (2328): udhcpc: lease of 10.9.8.2 obtained from 10.9.8.1, lease time 43200
Fri Mar 31 00:51:32 2023 daemon.notice hostapd: nl80211: Failed to remove interface phy1-ap1 from bridge br-lan: No such device
Fri Mar 31 00:51:32 2023 daemon.notice hostapd: phy1-ap2: AP-STA-DISCONNECTED 50:ed:3c:3c:94:64
Fri Mar 31 00:51:32 2023 daemon.notice hostapd: phy1-ap2: AP-STA-DISCONNECTED 4c:2e:b4:2b:dc:81
Fri Mar 31 00:51:32 2023 daemon.notice netifd: Network device 'phy1-ap2' link is down
Fri Mar 31 00:51:32 2023 kern.info kernel: [53537.046241] br-lan: port 7(phy1-ap2) entered disabled state
Fri Mar 31 00:51:32 2023 kern.info kernel: [53537.115519] device phy1-ap2 left promiscuous mode
Fri Mar 31 00:51:32 2023 kern.info kernel: [53537.120475] br-lan: port 7(phy1-ap2) entered disabled state
Fri Mar 31 00:51:32 2023 daemon.notice netifd: lan (2328): udhcpc: sending renew to server 10.9.8.1
Fri Mar 31 00:51:32 2023 daemon.notice netifd: lan (2328): udhcpc: lease of 10.9.8.2 obtained from 10.9.8.1, lease time 43200
Fri Mar 31 00:51:32 2023 daemon.notice hostapd: nl80211: Failed to remove interface phy1-ap2 from bridge br-lan: No such device
Fri Mar 31 00:51:32 2023 daemon.notice hostapd: phy1-ap3: AP-STA-DISCONNECTED xx:xx:xx:xx:xx:xx
Fri Mar 31 00:51:32 2023 daemon.notice hostapd: phy1-ap3: AP-STA-DISCONNECTED xx:xx:xx:xx:xx:xx
Fri Mar 31 00:51:32 2023 daemon.notice hostapd: phy1-ap3: AP-STA-DISCONNECTED xx:xx:xx:xx:xx:xx
Fri Mar 31 00:51:32 2023 daemon.notice hostapd: phy1-ap3: AP-STA-DISCONNECTED xx:xx:xx:xx:xx:xx
Fri Mar 31 00:51:32 2023 daemon.err hostapd: 20/40 MHz: center segment 0 (=114) and center freq 1 (=5510) not in sync
Fri Mar 31 00:51:32 2023 daemon.notice netifd: Network device 'phy1-ap3' link is down
Fri Mar 31 00:51:32 2023 kern.info kernel: [53537.326236] br-lan: port 8(phy1-ap3) entered disabled state
Fri Mar 31 00:51:32 2023 kern.info kernel: [53537.395526] device phy1-ap3 left promiscuous mode
Fri Mar 31 00:51:32 2023 kern.info kernel: [53537.400489] br-lan: port 8(phy1-ap3) entered disabled state
Fri Mar 31 00:51:32 2023 daemon.notice netifd: lan (2328): udhcpc: sending renew to server 10.9.8.1
Fri Mar 31 00:51:32 2023 daemon.notice netifd: lan (2328): udhcpc: lease of 10.9.8.2 obtained from 10.9.8.1, lease time 43200
Fri Mar 31 00:51:32 2023 daemon.notice hostapd: nl80211: Failed to remove interface phy1-ap3 from bridge br-lan: No such device
Fri Mar 31 00:51:32 2023 daemon.notice hostapd: nl80211: deinit ifname=phy1-ap0 disabled_11b_rates=0
Fri Mar 31 00:51:32 2023 kern.info kernel: [53537.578908] device phy1-ap0 left promiscuous mode
Fri Mar 31 00:51:32 2023 kern.info kernel: [53537.583929] br-lan: port 5(phy1-ap0) entered disabled state
Fri Mar 31 00:51:33 2023 daemon.notice netifd: Network device 'phy1-ap0' link is down
Fri Mar 31 00:51:33 2023 daemon.notice hostapd: phy1-ap0: interface state ENABLED->DISABLED
Fri Mar 31 00:51:34 2023 kern.info kernel: [53538.859468] br-lan: port 5(phy1-ap0) entered blocking state
Fri Mar 31 00:51:34 2023 kern.info kernel: [53538.865315] br-lan: port 5(phy1-ap0) entered disabled state
Fri Mar 31 00:51:34 2023 kern.info kernel: [53538.871253] device phy1-ap0 entered promiscuous mode
Fri Mar 31 00:51:34 2023 daemon.notice hostapd: phy1-ap0: interface state DISABLED->COUNTRY_UPDATE
Fri Mar 31 00:51:34 2023 daemon.notice hostapd: phy1-ap0: interface state COUNTRY_UPDATE->HT_SCAN
Fri Mar 31 00:51:34 2023 daemon.err hostapd: could not get valid channel
Fri Mar 31 00:51:34 2023 daemon.notice hostapd: phy1-ap0: interface state HT_SCAN->DFS
Fri Mar 31 01:21:45 2023 daemon.notice hostapd: phy1-ap0: DFS-NOP-FINISHED freq=5500 ht_enabled=0 chan_offset=0 chan_width=0 cf1=5500 cf2=0
Fri Mar 31 01:21:45 2023 daemon.err hostapd: could not get valid channel
Fri Mar 31 01:21:45 2023 daemon.notice hostapd: phy1-ap0: interface state DFS->DFS
Fri Mar 31 01:21:45 2023 daemon.notice hostapd: phy1-ap0: DFS-NOP-FINISHED freq=5520 ht_enabled=0 chan_offset=0 chan_width=0 cf1=5520 cf2=0
Fri Mar 31 01:21:45 2023 daemon.notice hostapd: phy1-ap0: interface state DFS->DFS
Fri Mar 31 01:21:45 2023 daemon.notice hostapd: phy1-ap0: DFS-CAC-START freq=5500 chan=100 sec_chan=1, width=0, seg0=114, seg1=0, cac_time=60s
Fri Mar 31 01:21:45 2023 daemon.err hostapd: 20/40 MHz: center segment 0 (=114) and center freq 1 (=5510) not in sync
Fri Mar 31 01:21:45 2023 daemon.err hostapd: Can't set freq params
Fri Mar 31 01:21:45 2023 daemon.err hostapd: DFS start_dfs_cac() failed, -1

It retries several times but still ends in that line:

daemon.err hostapd: DFS start_dfs_cac() failed, -1
dmesg
[53536.746182] br-lan: port 6(phy1-ap1) entered disabled state
[53536.805666] device phy1-ap1 left promiscuous mode
[53536.810629] br-lan: port 6(phy1-ap1) entered disabled state 
[53537.046241] br-lan: port 7(phy1-ap2) entered disabled state
[53537.115519] device phy1-ap2 left promiscuous mode
[53537.120475] br-lan: port 7(phy1-ap2) entered disabled state
[53537.326236] br-lan: port 8(phy1-ap3) entered disabled state
[53537.395526] device phy1-ap3 left promiscuous mode
[53537.400489] br-lan: port 8(phy1-ap3) entered disabled state 
[53537.578908] device phy1-ap0 left promiscuous mode
[53537.583929] br-lan: port 5(phy1-ap0) entered disabled state
[53538.859468] br-lan: port 5(phy1-ap0) entered blocking state
[53538.865315] br-lan: port 5(phy1-ap0) entered disabled state
[53538.871253] device phy1-ap0 entered promiscuous mode

EDIT: It happened again for a 2nd night in a row. Approximately around the same time. No need to post logs as they are nearly identical. Event trigger by:

daemon.notice hostapd: phy1-ap0: DFS-RADAR-DETECTED freq=5500 ht_enabled=0 chan_offset=0 chan_width=5 cf1=5570 cf2=0

This seems very similar to this older thread: 5 GHz WLAN craps out (upon radar detection?) - start_dfs_cac() failed - #9 by Borromini

I too am using 160 MHz width.

config wifi-device 'radio1'
  option type 'mac80211'
  option path 'platform/soc/18000000.wmac+1'
  option band '5g'
  option country 'US'
  option cell_density '2'
  option txpower '24'
  option beacon_int '100'
  option htmode 'HE160'
  option channel '100'

I added this line to /etc/config/wireless and will see if it helps to recover:

option channels '104, 108, 112, 116, 120, 124, 128'

Sorry to bring this up, but did you found a solution? Mine has the same problem and I can't even use AX mode with any bandwidth

It has been fine since I posted this and I still have the addition of that line I called out above.