Please watch video that I uploaded on youtube, it pretty much explains everything.
Saarvin + Fury + axe flurry proc = 6 hits. If this kills the boss the game will proceed to what looks like the experience screen results as I do have character that are ready to level up. However the game just softlocks and can’t proceed to presumably dice rolling.
I also had this happen against Argathakul at room 6. Same thing, the game will not proceed to the next room. This time Saarvin wasn’t guilty here, it was Shevarith.