Exposed Weakness
Did this twice, putting the fragility on all of the vortex crystals before attacking and then going around killing them in under 10 seconds. Both times the thing above my skill bar was showing me eligible for it. Finished the chapter both times with that still showing, and never getting the achievement.
Exposed Weakness: Redux
Completed this one once. Avoided the crystals while I had boons on me. Showed the achievement as being available when I finished and stayed until I left the chapter at the end without giving me the achievement. Same as the other one.
Edit: Better Red Than Dead
I have the achievement, but it still shows me as being eligible for it.
