Do you mean you don't receive any notifications at all for sometimes 2 hours ? Never had this problem but might need to do the usual wipe cache partition and maybe factory reset.
I am pretty sure this person means that certain notifications that are supposed to arrive right now come two hours later. It happened to me with email and Facebook messenger a few times; meanwhile, most of the notifications arrive in time
Ok that's interesting, I've personally not noticed any delayed notification but haven't really tested that properly to be sure it doesn't affect my device
