(edited by Xehanort.4589)
kitten bugged fractals
It is believed that the harpy invulnerable “bug” is due to a change made in game to thwart LOS glitching mobs/bosses. I am unsure if there are plans to fix this in the future. I typically run with the same players while running fractals and the only way we were able to complete this smoothly is to run as a group killing each harpy as you ascend.
As for the skill swap bug in Urban battleground I made a post and was quickly responded to. The Dev stated that they are aware of this bug and they are investigating. As seen here.
https://forum-en.gw2archive.eu/forum/support/bugs/Urban-Battlegrounds-Fractal-BUG/first#post2297191
But i hate as after the harpies push you down, when you get up again they may be at 60% chance invulnerable while still being in combat with them.