Archives quest "Fight Back"

Rayoname

I have reason to believe that the Challenge "Fight Back" in the First tome on the 4th level is bugged.

I was playing a game as Dwight

Perks :

Prove Thyself

Bond

Borrowed Time

We'll make it

I was playing against a Wraith that after 2 of the survivors got killed in a short amount of time felt bad for us and started "farming"

I dropped 6 pallets on him with the confirming "stun sound" the wraith gives from him and even escaped the trial in the end.

My challenge that says "Drop a pallet to stun the Killer 4 times within in a single trial."

Yet it is not completed.

Might there be a problem with the stuns counting while the Wraith is cloaked ?