Don't Receive Invites

I've been having this problem in which I can't get invites from my friends and/or they don't get a notification when I invite them. Its been occurring now for about a month or two.This problem seems to only be happening to me. My privacy settings aren't the problem. I also have an Xbox and Win 10 computer and I seem to be receiving invites on there just fine, its only on my phone that I don't.