Probably a common issue, yet very sad that it hasn’t been fixed. Loading up the game, reqs points, boosts, and just viewing your collection does not load. It just says retrieving data for a long time but never actually load. There’s an error message. I completed a warzone game and want to spend my req points on a pack but am unable to. Sometimes rebooting the game does solve the issue. Sometimes. Also, today a played an entire warzone firefight game without be able to access any reqs the whole game. 
Hard restart your xbox
Thank you for your reports. We’re aware and looking into it!
Yup everyone has the problem.
I experience this every time I log on to Halo 5, but it only lasts for 2-3 minutes before everything starts working fine. Usually it goes away before my first game finishes loading.
Having this same issue as well, has been saying “retrieving data” for 2 days no, does not show unlocked armors etc. please help as id like to get back online.