Friendship XP is Broken

I’m lvl 50 so I’ve been letting everyone open the final gift. I’ve found that I get the notification about half the time. The other times I see that we are now best friends, but don’t get notified. I’ve found that if I wait a day and open their gift, I sometimes get the notification. Any other tricks to force it to come through? I don’t play nearly enough to hit the notification limit, btw.