Stockades anima bug

In stockades nightmare dungeon (happen to be on level 16 nightmare), at last ‘phase’ before boss to collect anima and put into urn. I am missing 1 anima (not 1 anima carrier, but 1 anima). It looks like one carrier only dropped 2 instead of 3. Can’t complete the dungeon and have run the entire area three times now to verify there isn’t one that I missed to pick up.
What a waste of time. I don’t get why I play such a broken game.