I've run the quest dozens of time on N, H, E, EN, & a few times on EH. Once in a group for EH, and 2-3 times solo. Out of the dozens of times that I've run it, mostly every single day for a month or more straight after I had my PM hit lvl 20, I have never run into the issue on the Ghallanda server.
Seriously though, if you want this bug fixed, and I mean anyone who has run into this more than once, give a detailed report or video of how you run the quest, as well as important information. Otherwise, it's no wonder thing bug hasn't been fixed, with so many unwilling to help pin point the issue.