OK. I have also spotted one or two instances where a dialogue seem to lock further action for a player.
My wife suddenly reported that while I was otherwise engaged, she cold only run around and look at the scenery.
No interaction possible. No opening containers. No talking to strangers.
Since my game crashed shortly after with a "black screen of BG3 death", I forgot to investigate further.
This was in the first visit to the grove after talking to Cold Ethyl.
