On bad connection you just have to wait. I aso often don't see my notifications for a while, it needs to sweep the relays first.

Ive noticed that too... I always have to flip it global then back to follows to actually get the feed working. I guess it will never be able to be perfect. Or the filtering also effects the notifications... maybe its that. a times dont see people commenting on post im tagged then when another person's notification comes i get to see more answers there i never got a notification for. 🤷‍♀️✨️