The doorbell installed at the front door is no longer providing any push notifications for motion or people at the door. Doorbell has been disconnected and reinstalled, Nest app has been uninstalled and reinstalled, devices are not in Do Not Disturb, notifications are turned on in both nest app and Home. Doorbell (push) notification works, and camera is recognizing when people are at the door, but not providing notifications.
This is a long shot by try doing a full power down of the phone and then power it back up after about a minute. Sometimes having the phone de-link from the cell site and then re-linking can make the alerts start working again. ... worth a shot at this point. Please let us know if it works.