@Riley_S I agree with that. There must be some issue between the TPlink switch and the ASUS blue cave router. Since the blue cave is already in the list of EoL, I can not expect any firmware update...

@Riley_S Sorry, my bad. The model should be HS220, Smart Dimmer Switch single pole. I have tried guest network. By connecting the switch, the guest network disappeared and the regular 2.4 GHz and 5...

When I tried to connect KS220 V2 to my router (ASUS blue cave), the connection would cause my whole network to crash. 2.4 GHz SSID disappeared, and 5 GHz still detectable but no internet connection....