My notifications have been delayed on my xbox one since day 1. I will get the achievement but wont get the notification for like 1-2 minutes later. The same goes for messages or. I would really like them to fix this. Its not a game breaking issue but its rather annoying, like i wont recieve game invites or party invites untill like 2 minutes larer. Sometimes dont get them at all. It gets rather frusterating. It has got to be on there software side since i know other people that have this issue.