I noticed my devices were offline. I did the usual steps, restart habitat, restarted network. That usually brought it back in the past when this happened. But not this time. So I tried reconnecting habitat from the Google Home app. It fails with this message. "The parameter "state" must be set in the query string"
Sorry, I don´t have an answer for you, but I have a similar problem.
I also did the reconnect, even threw out the old Google app, wanting to reconnect it on the hub, but it seems that it is not a built-in app. So now I am essentially not pushing devices to Google Home.
Not sure if this has all changed drastically. I simply setup Google home several years ago and I have not had any issues until now.
I did some research and it seems that the previous method of connecting to Googl has been changed. I got things to work again by unlinking Hubitat and then roughly following the instructions to re-connect. Google Home | Hubitat Documentation