Facebook app notifications issues on my iPhone x

Hi there!

I have a problem with the Facebook app notifications on my iPhone x. Practically everything is on and up to date, but I did not receive any notification on my mobile from my Facebook account.

The surprise was huge when this problem disappeared as long as I was logged on my girlfriend account! This means that somewhere between the desktop version and my iPhone something is wrong. Can you figure out what could gone wrong? I studied the settings through my laptop on my desktop version, everything appears to be ok. I really don't know what to do, do you have any idea?

Please note that until September, when I upgrade from iPhone 6 to iPhone x, this issue did not appear. Thanks in advance!

Dorin