I just had an issue with this path as well. My group got all the traps built and we got the traps charged up, but the ghost eater freezes in position and will not take any damage. The party isn’t taking any damage either.
Anyone else getting that issue?
By running away from the boss we got it to reset. When we went back we were able to pull the boss and damage it for a moment. We even got it over to one of the traps and caused the trap to discharge.
The boss then bugged again and stopped taking damage again. The party was no longer taking damage again as well.