Pretty sure mine says 1, but will check later.Until recently I’d never seen a notification - hadn’t really thought about it until needing to use SCs recently.
After checking IOS/car settings - I had a look under settings in the app - and noticed Notications/Selected Vehicles showed Vehicles 0.
No reason I can see for this - although I did have the app installed prior to car allocation.
Tapped it, selected my car, it now says Vehicles 1. Notifications work now. Glad - because the day after I left my Mum in the car with walk away lock on - and guess the notification I got whilst in the Woodall services?!
From the diagnostics - it won’t be the fix for most of the reports here - but in case it helps a few passing readers worth mentioning my dumb-arsery.
Presumably even though yours said zero - you could see your car and control it? (opening windows, etc).