The footage from a particular 12hr period from a particular device appears corrupted on the server side. I see that my Nest Hub Max device restarted at 3am and then again at 2:15pm on the same day. In between that time, the footage is not viewable on any platform but activities/motion/sounds and clips show up on the timeline. Probably a firmware update that had a bug so they had to revert back. That's my best guess. I reached out to Google but it's impossible to talk to anyone at a company that big that actually knows what they are talking about and has the tools to fix things. Does anyone have any ideas on trying to recover the footage or am I just SOL?
Sorry to hear about the trouble. I wanted to follow up and see if I could be of any help. I found an article with some troubleshooting steps. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.