@Benji409 If this is Windows PC, try its "Network troubleshooter", also check Microsoft article "Fix network connection issues in Windows" and also do "Reset WiFi Network Adapter settings" You should...

@Benji409 If you need quick solution, bring one of Satellite Deco close to PC and connect them with Ethernet cable.

@kamikaze2001 Your air conditioning system does not understand WiFi mesh. Keep router 2.4GHz WiFi enabled, with SSID different from Deco. Connect air conditioning system to router's WiFi.

@KWK Yes, you can.

@Jason21210 If you run Deco mesh in Access Point mode, you can connect powerline adapter to ISP router. In case you run Deco mesh in its default router mode, powerline adapter must be connected to...

@14paavang Deco M5 if you can still find it in retail. Also, Deco M9 Plus. Both have Connection Preference feature in release firmware. Both these models are WiFi5, in general expect M9 Plus be more...