So Arma 3 basically stops working when joining a server. It usually happens when it's the second or third time you're joining the same server. If I keep waiting on the loading screen (after a very long time) I can notice I get kicked by 'BattlEye: Client Not Responding'. If I try to forcibly close the game I get the crash message. It's either 'UNABLE_TO_INIT_DXGI' or 'APPLICATION_HUNG'.
I checked that with a few other friends and they seem to be facing the same thing occasionally. It does happen in different servers as well.