I've submitted an in-game report, reported it several days ago via the Internet bug report feature and replied to the automatic email I received, and I also reached out via Twitter and still haven't heard from ZoS about the problem.
I ran Direfrost dungeon, Noble's Rest quest. We killed all the bosses, completed the dungeon, yet I never received credit for killing the final boss. The quest still asks me to kill it. Ergo, I have failed to receive experience, the skill point, and the credit. I'm trying to avoid abandoning the quest and re-running it. I shouldn't have to, and I would've expected a reply by now too to one of my bug reports.
I took two screenshots to show the final boss area, empty, but an unfulfilled quest.