The work -a-round I have used is to disable AUTO for the Wifi Channel, Channel bandwidth and Power and set your preferred options for each. In my case I have set the Power to High in a hope that the external AP’s that check channel utilisation with prefer a different channel than the one I have manually entered.
However I’m not sure if your Interreference is from your other Alta AP’s and the Alta Algorithm backs off and shuts AP,s down due to this interference. A sort of Catch 22 situation. When you do a Full wifi Scan from the various AP’s do you see your own SSID’s as the strongest ?( lowest dBm value) I believe you have four AP’s and with Alta preference for the Three standardised channels there will be conflict if the AP’s are physically close enough to each other.
This is just my opinion based on what I understand about the Alta AP’s and I may be wrong. I have no knowledge on how the Alta Chanel utilisation algorithm operates with alta AP’s that can “see” each other. I only use 2.4Ghz for IOT devices and Printers. All other devices connect to the 5Ghz channels