I have 3 battery powered Nest Outdoor Cams and they behave the same way as your Nest Indoor Cam. When I click on a camera’s black screen, it live streams in a popup window.
I’ve tried to change the Camera View to “Live” but it only works with 2 of them. There was a “limit reached” error of some kind when I tried to have all 3 cameras live streaming on the same dashboard. HA is installed on an old Macbook Air so it might not crash but I haven’t tested it long enough to be sure.
Hopefully, I can find a way to see an updated screenshot of the last event instead of a black screen. That way, I could just click or tap on it for a live stream.