@Ziesie Hey, a helpful post here you can take a look: Custom DDNS Is Not Working

@dasdasdas It's weird, did you check the wired network? Was the wired network stable when these wireless clients dropped? You can check the IP address on the phone when the AP dropped, close to the...

@J-O So did it work on the iPad if disable this option?

@dasdasdas What is the remote clients connecting to the AP? What is the signal strength on the clients? Did you set the power save mode on them?

@J-O Check if you enabled the Private MAC address on the ipad, and disable it.

@Skippie I don't think it's smart enough to detect it like you said"not upgrade the PoE switch while the AP's are upgrading", suggest you set the separate upgrade schedules for them.