Kosis stuck out of bounds

Reference ID: 3390007868
In Clearfell Lumbermill simulacrum, wave 10, Kosis has teleported/spawned out of bounds and I am unable to damage him to progress with the simulacrum. It's in the really narrow part that loops back to the beginning. I think I can hear him to the upper left. Portaling to hideout does not fix it, nor does logging out/in, nor dying. I also see the marker to start wave 11, but I can't interact with it.