I just restarted the phone and before restarting I noticed there were a few YouTube notifications. Once the restart was done, these notifications just vanished.
Is this supposed to happen? Doesn't seem very comforting as I will never get to know what my pending notifications were every time I restart my phone..
Yes, it is normal behaviour.
But there is already a suggestion about it in Suggestion category and it has been forwarded to the development team!