Temporarily suspended (30 days) and I don't know why

My brother and I have family sharing on steam.

He got Arc Raiders on release and I didn't because of kids and family etc. He's been playing for hundreds of hours.

Yesterday I installed the game and played two games. Both groups had other players using party chat, so I did as well. Just casually asking about the game and they helped me out. Died first game, survived second. No loot on anything since I barely had any idea on what I was doing.

Today my brother tried to boot the game. He was hit with a temporarily suspension. 30 day ban with no reason. Just a message telling him to contact support.

Now I feel bad. If anything I did was my fault for the ban as he enjoys playing the game. I know for a fact I didn't do anything that breaks any rules (except being new and bad at the game).

I do however run the game on Linux. Fedora 43 KDE. Can that be an issue? One of my party members dropped me a heavy machine gun that I managed to save during my second round. Is that not allowed? Other that that I have no idea what else it can be.