Here’s another thread on it. It all happened the same day, including
mine.
https://www.googlenestcommunity.com/t5/Cameras-and-Doorbells/Google-Nest-Doorbell/td-p/717531
They don’t seem to understand that it’s a widespread problem. I’ve
talked to two people on the phone with no resolution. Mine has been
elevated to a senior engineer and they’re supposed to contact me in the
next one to two days. I am not holding out ...
Mine is doing the exact same thing. It just randomly stopped the
notifications last week. I even upgraded to the Nest Aware subscription
from the Nest Aware 1st Gen subscription and that didn't help.