I've submitted a ticket and sent an e-mail about this already but there has been no response.
In the quest Stonefire Machinations in Reaper's March, I can successfully destroy the anchor, but upon entering the temple all the mobs (including the Mane) have only 1 HP. The mobs are killable but the Mane is not -- even after his unit frame reads "Dead" he still continues attacking, very much still alive, and I do not receive quest credit. I have tried abandoning the quest as well as travelling to a different zone for a long period of time to reset the instance... but the issue remains after many tries. As this quest is part of the zone quest line, this bug is preventing me from progressing through the rest of the zone (and by extension, Coldharbour, Cadwell's Silver/Gold).
I've attached screenshots of Mane Akkhuz-ri at 1 HP and "dead".