Xiaomi 4C wifi crashing

Greetings! My Xiaomi 4C wifi is crashing without any crash log in log file. How I debug it?.. Crash is very random, it can be any time and only router restart helps. Version is latest, 21.02.1. Here is mine /etc/config/wireless.

config wifi-device 'radio0'
      option type 'mac80211'
      option hwmode '11g'
      option path 'platform/10300000.wmac'
      option cell_density '0'
      option country 'GE'
      option htmode 'HT40'
      option noscan '1'
      option txpower '14'
      option channel '13'
      option distance '15'
config wifi-iface 'default_radio0'
      option device 'radio0'
      option network 'lan'
      option mode 'ap'
      option encryption 'psk-mixed'
      option key 'secretkey'
      option ssid 'somessid'
      option disassoc_low_ack '0'
      option max_inactivity '10800'

Can anyone help with this problem?

Anyone please?

My 4C use:

option encryption 'psk2'

no crash, maybe not this reason.

Did change to it, thanks. I will reply you if crashes will be gone. My router also restarts everyday at 2:30 A.M. If someone can, tell me best way to debug, if log file doesnt work.

Btw, I donot have those lines:

      option cell_density '0'
      option noscan '1'
      option txpower '14'
      option distance '15'

      option max_inactivity '10800'

Did remove them. I'll see if any crash will occur. If there will be crashes, I will have to return to stock firmware, sadly. Max inactivity is set to that high value because of some of my devices disconnecting from wifi constantly.

UPD: 1,5 hour without crashes. That's good.

One more crash. Is there any valid solution?..

Back to a clean OpenWrt factory img and default configs, just enable wifi as AP, check if no crashes.
if still have, then back to Xiaomi Factrory img, to comfirm hardware.

Check your wifi devices/phones, maybe compatibility problem.

I found the problem. I did set station inactivity setting to 1500, so now wifi doesn't crash anymore O.o. If anyone knows good tool for debugging, please, tell me. Possibly, some device was crashing my router by just going to sleep. Can't really debug that. I will update this message if problem is gone.

Hello! I did return to stock firmware and it is more stable. Also internet connection is more stable than on OpenWRT. Thank developers for putting much effort in it, but Mi router 4c is very unstable in OpenWRT.

I set two identical SSIDs, it seems not to crash now.