wE DONT KNOW WHY WE WERE BANNED - PLEASE EXPLAIN

My 11yo son was playing Halo Reach and then received a message to say he was temporarily banned from earning credits. We are new to Xbox and don’t know why he was banned. Can a moderator please tell us the exact reason he was banned so that he will know not what to do in future?
Thanks

it may be a bug, but i know about people that recieved the same messages, i think if you wait a little bit, it may get fixed, or you need to contact Xbox support.

AFKing (no kills in multiple games)

Cheating

cR boosting

For a first offence, it is only a day long. Future bans will last up to 2 weeks.