I had issues with setting up the camera on my 2nd Nest Hub Max. Like others, it would stay offline and the camera wouldn't function but all other functions with the Hub was fine. Furthermore, I had removed from my Google Home, my 1st Nest Hub Max (whose camera was working) and, when I tried to install it back, I'd have the same issue with the camera.
Anyway, thought I'd share that, after a lot of trial and error and reading other threads, I got both to work.
It looks like if you have other Nest Cams installed on your Google Home, the camera on the Hub Max won't (I'm guessing this is the same with the Nest Doorbell too).
Anyway, I removed every Nest Cam from Google Home (I have other non-Google devices linked to Google Home but kept those connected). I factory-reset my Nest Hub Max and installed from scratch. At first, it still didn't work except, unlike before, the green LED light was now on. So I then went to the Nest App and the live-stream was visible. I went back to Google Home App and now it was working ok. I did the same with my 2nd Nest Hub Max and now they both worked fine. Again, in both cases, the normal installation seemed to go OK but couldn't get the live stream unless I activated the Nest App first.
Afterwards, I added back all of my other Nest Cams (I have two battery-operated and one wired) and, now, everything is ok.
It's a major pain ... but at least it all works now. Hope this is helpful.
