I had the same problem a while back (connection being dropped). I did the trick with dividing WiFi to 2.4 GHz and 5GHz, was working for a while on 2.4 GHz (~ 2 months). Since a few days, the projector does not even bother to connect to ANY WiFi anymore, it does not even see any network. The slider jumps back and forth by itself (switching itself constantly 'on' and 'off'). Did the factory reset (multiple times), did not help at all. It fails now to go through any online configuration, despite of having additional hotspots in its range (from cellphones) and even alt. router. If firmware would have been downgraded with this factory reset, I would have at least an idea, if it's a software / hw problem.
i can cast from my iphone to the projector without any problem at all.
however, when i open the google home app and click on the projector, google home still says that it can't access the projector and to try making sure both devices are on the same network.
I thought about deleting the projector from google home and trying to re-add it, but i cant see how to re-establish it as a chromecast device and I'm worried that if i delete it i wont be able to add it again and the ability to cast will be lost forever.
i discovered this as I wanted to turn on 'ambient mode' on the projector which you achieve via the google home app.