i'm having the same problem. for some reason my baldur's gate iii has not been able to connect to my steam account since last week, resulting in 1. i can't invite by steam and 2. i can't get steam achievements. my friend and i were in act2 just before killing thorm, and there is an option for Gale to explode himself, hence achieving an ending. when the game ended, i was wondering why there were no achievements for endings, and my friend told me he got the achievement. also i am the host.