Bug in Ebony Tower

[Ayezar]

So I was climbing up the Ebony Tower going up the ladders to the left from the entrance, and I got stuck after reaching the room with the Ash Lord (not sure if I remember the name right). The reason I got stuck is because apparently I managed to go through the earlier floor without spawning the Fiend.
What happened was that I went up a floor and the character I was controlling was able to climb the next set of ladders without moving, so the Fiend appeared when my party got to the next floor instead.

I did try it again, but I think because I was controlling my main character I wasn't able to reach the ladder like before (I think I was controlling the character on slot 4 on my first try). Similar thing also happens by going up some ladders to a room where a Fiend was supposed to spawn, and then going straight back down, which then made the Fiend spawn on the floor I just left.