You have to add new cameras with the Google Home App. If memory serves
me correctly, then it will show up in the google app, but not in the
Nest App, and at least when I worked with it in September, 2021, ability
to get histories was all screwed up, ...
I just purchased and installed the new battery operated indoor/outdoor
nest cam with constant power. MUCH to my dismay and can ONLY see my
history in the Google Home App (which crashes on my iPad ever few
minutes) and NO history of my 8 older cameras...