On Swift Wings
Dont chase warriors. (Blackgate).
https://forum-en.gw2archive.eu/forum/livingworld/s2/On-Swift-Wings-bugged
https://forum-en.gw2archive.eu/forum/support/bugs/On-swift-wings/first#post4222264
These 2 threads confirm this bug it is thought to be due to the NPC’s not going through the portal in the lab and exiting the instance, therefore the achievement does not trigger and when the last “defend the lab” event is triggered the NPC’s all automatically die in an unrezzable position outside the instance, thus bugging this achievement