Okay, keep having issues with the quest.
I'm over level for elite, but trying to grab the favor and the bits of xp from it I can still get.
It has now happened 5 times at the same place and once earlier on. The first five were right as I started opening the last chests, the most recent was at the first turn off from the main sewer line.
Each time I end up being unable to move, but my character still emotes (making jumping look like squats) and will turn into that for hours until I get to tab out and quit, and if I log back in, it puts me right in the same problem.