@David-TP finally, and hopefully this was the solution; smart DHCP was on. This was on in AP mode? that's crazy that this is possible. But for me that was the problem for now! devices receive an ip...

@David-TP Did Deco X20 turn red when Wi-Fi goes down after connecting a switch? Yes about 30 sec. Have you tried to connect the switch behind one of the satellite Deco X20 to check whether the same...

from May I can no longer connect a switch to my main deco. it has always worked for that. (2 years). So when I connect a switch to my main deco or modem, my WiFi goes down pretty immediately. Have...