In the place you reached, there should be red armor in the center of the arena. She triggers the final encounter. Very unlikely, but quite possible, some monster was thrown out of the map, killing him did not count and this armor did not appear. I will look at this place and try to fix it so that this error does not happen again. But now you need to replay this level from the beginning.

Alright, I restarted the level and it did not get stuck this time. Thank you.