Check out this thread:
iPhone notifications stopped working
... particularly the posts on the last page.
A guy managed to get hold of a “level 2” Tesla tech who confirmed that his car was stuck in some kind of transient service mode from a previous appointment. This state meant that no notifications from his car were being sent by Tesla servers.
His phone app gave no indication that this was the state of the car (i.e. it didn’t say “in service” like it does when it’s actually at a SC)
I’m having the same problems (no notifications since recently, despite several software changes and complete reinstallation of the app & reset notification settings - which have always been the same). I have also had a few mobile and service centre appointments in the last couple of months, two of which were cancelled due to parts availability. I’m convinced my car is stuck in this “pseudo service mode” limbo as well.