Ring Alarm - Unable to connect or see Wi-Fi.

My Ring Alarm and Eero network have been playing nicely since March. A few days ago my base station lost Wi-Fi connection and been running off 3G. I've followed the instructions in the app to join another network but it can't even see my network. The ring stickup cam under a metre (further away ) is working fine. Tried the usual like rebooting the router but it hasn't helped. Anyone got any suggestions before I sit on the phone tomorrow waiting for help?