@Kevin_Z When I plug the ethernet Cable , the 2.4 ghz wifi goes, and when i tap on the 5ghz wifi it says denied access and it also goes. i have checked other routers and they work. i have tried...

My Archer C20 router is only 12 days old and now WiFi is not showing and it's saying it denied access when i connect the ethernet cable, when i remove ethernet cable and only power cable is connected...