AX86U not sticking to selected channel on 5GHz

[Volfi]

I have my AX86U set manually to channel 108/80MHz, but stock firmware (latest version) does not seem to respect this. After few minutes the router migrates 5GHz band to channel 40 or so. How can I prevent this? It will be probably some UI setting, but not sure which one 160MHz is off, AX is on.

2.4GHz band seems to stay on selected channel (13 for me being the best).

 

[Volt]

That's because 108 is a DFS channel. Probably your router detects a radar and switches to a non-DFS channel (as required by regulations). There is nothing you can do about it.

 

[Volfi]

That makes sense. Thank you!