AP mini stop serving traffic in mesh mode

Hello! I found a strange behavior with AP Mini that I cant fix.

This issue was there from the beginning but not I isolated problem.
I have a setup at home:

  • Balance 20X connected to WAN and serving both: 2g and 5g wifi
  • Balance 20X also has mesh on 5g
  • In direct visibility (~10m) there is AP mini
  • Balance 20X uses AP controller to setups AP mini
  • AP mini has a separate profile for wifi
  • AP mini uses same mesh on 5g
  • AP mini serves another wifi on 2g on a separate SSID
  • AP mini 2g and Balance 20X 2g uses different channels
  • All channels are different from neighbors
  • There is only one device connected to AP mini wifi: macbook
  • This macbook only used for work and most heavy wifi task is zoom call.

The issue is that time to time (once every few days) AP mini stop working. Symptoms:

  • Power light is green. Wifi is always green or blinking
  • Macbook (and other devices before) is able to connect to SSID but IP is self assigned and not traffic
  • Restarting AP helps
  • Waiting ~25 minutes helps
  • From router page AP looks down (grey in list) and chart on dashboard shows 0 clients are connected
  • Weird thing [noticed today and need to double check]: after AP is healthy again I see that chart on balance 20X shows like AP was always healthy with one client in historical view.

Have anyone seen it before? Maybe some ideas what to check?
Any help much appreciated.