This bug has been around a very long time. I had trouble with this quest as well as a few others, but it seems very limited. The ISSUE is that when you have area loot enabled, it clumps all of the loot and mission items together and when you hit take all, it does not update(Where in lies the issue I believe). Try turning off area loot, and just loot the yellow beams individually. (You can still possibly use area loot enabled, yet instead of hit TAKE ALL, just click on each mission piece individually in the list. I have had it work that way.) I have done all heroics listed in the new reward format for the expansion for each faction. I have been able to complete them all, even the ones for which has this bug. Try this, if it still does not work, update this post for dev review.

This bug has been around a very long time. I had trouble with this quest as well as a few others, but it seems very limited. The ISSUE is that when you have area loot enabled, it clumps all of the loot and mission items together and when you hit take all, it does not update(Where in lies the issue I believe). Try turning off area loot, and just loot the yellow beams individually. (You can still possibly use area loot enabled, yet instead of hit TAKE ALL, just click on each mission piece individually in the list. I have had it work that way.) I have done all heroics listed in the new reward format for the expansion for each faction. I have been able to complete them all, even the ones for which has this bug. Try this, if it still does not work, update this post for dev review.