I feel your pain. My group isn't quite that bad. However I was sent home for being 15 minutes late, without having previously been warned that this was a policy.
My group has the same kind of thing when it comes to one person being more talkative. but again to a lesser extent. He talks a lot aand there's one girl who refuses to talk. As well. Sometimes I wanna give up on group but ultimately I know it's good for me.
Best of luck.