WiFi issues - ethernet connection works, Xfinity hotspot works, My WiFi does NOT connect

WiFi issues - ethernet connection works, Xfinity hotspot works, My WiFI does NOT connect.

I am currently connected via ethernet. My mobile devices (Pixel 3, Iphone X, Surface laptop, Ipad) will NOT connect via our regualr WiFi connection. And the Xfinity hotspot DOES work.

I have reset the gateway 3 times - twice by unplugging, once via the service portal chat.

I also cannot access the admin portal at all (via 10.0.0.1). It will not open.

We have the Xfinity gateway (Arris TG862G). No problems for years until this week.