Ok so I have a 910C and a 902, each covering different parts of the house. same SID ID. Wired back to the same 2860 in the attic.

Apart from channel allocations all other settings look the same.
My 910C stays on channel 112 for 5Ghz. Exactly as specified and set.

However my 902 never stays on its allocated channel what ever is allocated. I set it to Channel 60 and within hours or next time I check it has changed channel, itself!
I have ,manually set channels in the Advanced Settings, Auto Channel Filtered Out List, and it even re allocates itself onto channels I have told it not to.

Is there any easy way to fix it to main channel 60 on 5ghz? and to stop it changing channel itself?

Thanks.

Have you got management enabled... ?

Yes on both devices. 902 and 910C

Disabled it on both to see if there is any difference.

Still the same. 902 changing channels with AP management disabled.

I meant autoconfig, autodepoymentor whatever it's called, but then so did you problably

This is happening because of frequency regulations for 5GHz wireless networks - which must implement Dynamic Frequency Selection for channels 52 to 140. This checks whether radar can be detected operating on the specified frequencies in that range and if so, will switch to another available channel, potentially falling back to non-DFS channels where required (36 to 48).