Stuck in simulacrum Wave 14/15

i'm presently doing a Simulacrum. I did kill all the mobs and i didn't get the loot.

The NPC appears to let me lcick next wave but nothing happens. I still can hear a mob but that mob is dead.

Is there s way to reset or unstuck?

Just happened to me to... stuck in wave 14 and cannot continue. did you find any solution?