Yes I am aware about the red dots, none are on the compass whenever I cannot finish the quest.
I said in the original post I have gone in debug mode and flown through the ENTIRE POI, top to bottom, so it is not possible that there are zombies I am missing if I have flown through the walls and floors to look for the last zombie. I have tried the KILLALL command in the F1 Console aswell but it has not worked.
The latter explanation is the more likely one it seems, I am not sure if anyone else has had this issue but I will begin to noting down which POIs this occurs at.
Not to sound obnoxious but there seems to be nothing that I am doing to cause this issue, this is either a bug or something else wrong with my friends game.
Gonna try some things in a bit to remedy this issue.