Why can't I play this game online?

I was apart of the halo 5 multiplayer beta, enjoyed it greatly, and bought the full game 3 days ago.

Every time I start up halo 5, the game says “We couldn’t get your latest saved data”, it then gives me a choice to “try again” or “use offline”. “Try again” never works, so I have no choice but to use “use offline”. The game then prompts me with “ATTENTION unable to connect to the halo: 5 Gardians Lobby Service.”

this is HIGHLY frustrating because I bought this game with nearly no interest in single player.

For reference, i have at&t, open nat, Mcafee security, and have tried a hard reset. Any help will be appreciated.

Bump

Have you tried reinstalling it? also I don’t think this is place for help troubleshooting bro
https://support.xbox.com/en-US/xbox-one/games/halo-5-guardians-multiplayer-troubleshoot