The quest turns up, but even after seeing the map, Winston's desk, and talking to him, the "turn it in" button in the quest menu is grayed out and can't be clicked.
Did you check the desk prior the quest was given? In your inventory, is there a culprit icon? Looking at the code, I think the only reason the culprit item is not in your inventory is if you have checked the desk before the quest was given and you had the "Vampire Monarchy" topic at that time.
another fix is to talk to Winston at the sparring field after you have checked his desk, and the option to report him shud pop out
If that doesn’t happen, would you mind if I contact you via discord or the sort to try and test out a fix?