Please see the pinned post: About the Vermintide 2 - Bugs Category to see what information to include in your report.
Just got done doing Enchanter’s Lair for the event, and Nurgloth has a weird bug. I was carrying the Skull of Blosphoros throughout the run, no issues, and then during the Nurgloth fight, right as his health got to the “T” in ‘The’ (Nurgloth the Eternal), his health bar stopped moving, I continued wailing on him, but never any progress on his hp. Finally, about 6-7 minutes later, I decided to destroy the Skull of Blosphoros and see if that did anything. As soon as it was destroyed the boss instantly died. Very frustrating as it didn’t count toward my progress of finishing 5 matches while holding the skull, and obviously I was able to complete it with the skull in hand. Would love to see a patch come out ASAP for this so it doesn’t ruin anyone else’s runs.