Trial of chaos bug

Good afternoon.

I suppose there is a bug in Trial of chaos room where a monster stands on top of a platform and I cant reach (hit) him there. And I cant pull the platform down of course because it suppose to go down after all monsters are dead. I only can exit to log screen what leads to waste the whole Ultimatum.

Bug report reference number 1 904 803 857

Screenshot:

https://dropmefiles.com/Likqr