I just took a look at an article on vacations and it looks like you have to uncheck your "I'm on vacation" box in settings. Yeah, I know you didn't check it in the first place, chess.com did. Anyway that's my take on this article:
https://support.chess.com/customer/portal/articles/1444894
I just got a message saying my 54 minutes left in a game triggered a vacation, and I can't move in it.