Simulacrum Boss disappeard - Last Wave (15)

The Last boss in wave 15 disappeard while i had him almost killed!!! omg






After i when to my hideout and went back to the Simulacrum are i saw the Waves-NPC with "Wave 16/15" but i could not start it - nothing happend......crazy bug

It says 16/15 when you kill all waves, its not a bug its how game says ,,simulacrum is finished,,. Normaly you should see your last loot on the ground when this number is displayed but if you dont see any than thats a bug indeed

The boss had like 1/5 of his life and he disappeard and nothing dropped. it is indeed a bug and the quest even is still open.