Router does not maintain Wi-Fi channel

Sycret

WindTre-branded ex5601 router
I set Wi-Fi channels 1, 2, or 3... 2.4GHz
It lasts a day, then it always switches to channel 11.
The problem is that with the high channels, my Wi-Fi printer and video camera system no longer work (the devices connect at very low bitrates, the printer isn't even visible).
Why does it do this?
Until a few months ago, it was constantly on channel 3. Is it possible that a firmware update caused this?

CryBananaCat

HI~

It is likely that the "Background Scanning" feature in the firmware is enabled. When the router detects interference on channels 1-3, it will automatically switch to a channel it considers "cleaner" (such as channel 11) in order to "optimize connection quality."

I recommend that you contact your local service representative for further information or assistance.