“Your switch isn’t responding. Please check its power and wifi connection.”
ARRGGGHHHH!!!
I spent month trying to resolve this. There is all kinds of voodoo on the web, but here’s what worked for me.
1) Find the least used channel from 1, 6 and 11 in your 2.4 settings. Use that channel. (6 is usually the most crowded, followed by 11 and 1, but you need to check actual conditions in your location.)
2) Unless you need 2.4 N, reduce the bandwidth from 40 to 20.
If that doesn’t work, then…
3) make sure you are WPA2/WPA3 PERSONAL for your login, and make sure you use the same password on all your bands.
After making the changes, unplug all your wifi plugsfrom the wall socket, wait 20 seconds, and plug them back in again.
HTH