none of my connected switches and sensors respond to the home app

None of my wifi activated switches or sensors respond to the home app or to the vendor app. I have tried multiple times to restart individual switches but never get them to activate although they seem to be connected to the Wifi

This appears to be a problem in the WiFi or home app not the devices themselves

it worked flawlessly until they all failed at once while we were away.

My camera and Nest thermostats all work fine

ANY ideas?