I have a xiaomi compact projector that has chromecast built in.
I had it set up in my google home app and it was working fine for months until an android TV update back in august rendered the projector's wifi broken. The update also stopped any ability to cast to the projector.
That was finally fixed this week and it's now working fine and I can cast to it from my iphone once again.
However, when i go back to the projector in the google home app and try and access any settings I simply get a page saying "disconnected device". The projector is on the same wifi network and there's no obvious reason that I can't access it from Google Home.
I thought about deleting it completely from Google Home and then trying to re-add it, but I can't see any obvious to to re-establish it as a chromecast device and I don't want to lose the ability to cast that I at least have now.