I remember a weird thing with Florrick's cutscene. Not exactly the same as what you describe, but similar. Maybe this could lead to a solution.
I sent Karlach in the burning house alone. There's no need to send the entire team inthere. Karlach is fire resistant and strong enough to break down the door. So Florrick is freed, runs toward the exit, I follow behind with Karlach, and then before momma K can exit, the cutscene starts. But it doesn't really finish because my selection is still on Karlach who is still inside. Going back to Karlach and leading her out then continued the cutscene normally.
If this happens, check if all party members are outside or if maybe some are still inside the house.
There was a similar problem in the barn in Rivington, when you're inside and the guard wants to take you to Nestor. You can't get to Nestor and remain stuck unless all the characters are in the right place.
It's a bug, but there was a way out by switching between the party members and trying to regroup.
