Error authorising user when connection to lobbys

Hello my mate having trouble connecting to multiplayer lobbies my mate gamertag is TeamoFVardyZ89x keeps coming up as Error authorising user he got told from Microsoft support he could be banned either temporary ban or completely banned how long is he banned for or can u help to resolve this issue for him can’t see how because he only played Co op with me and did a few missions he hasn’t played a multiplayer match game yet

I doubt he is banned I would maybe reinstall the game or attempt a log in from a different console.

He’s done that he still can’t get on it