Not this time, no. I think it was the case another time. As I said, it was after other rounds of normal combat.
I just had another strange occurrence. This time, my party was hidden on a platform above enemies. Astarion launched a fireball at an explosive, which killed all enemies except one. The enemy shot at Astarion and only the two of them were in the combat queue. Then Astarion made a sneak shot, after which others of the party started to be added to the queue. The exchange continued for 2-3 turns, but only Astarion and the enemies could play, as if there was no one else, and even if others were in the queue.
We were all in the same group, very close to one another.
There's definitely something broken when starting the fight in some conditions.