My partner and I are attempting the achievement to go from the floor to the top ledge all in one go in Lucent Citadel. She was able to get it a few minutes ago, and when she told me how she'd done it, using the blue orbs, I had about two attempts before all the orbs just disappeared entirely. Exiting and re-entering the trial did not fix this. After trying repeatedly and getting just shy of the ledge on numerous subsequent attempts, I believe this problem makes the High Flier achievement impossible to attain until the trial is reset and the initial bosses done again.
I see no reason we should have such limited attempts at a platforming mechanic, especially one that feels terribly finicky and out of place in an RPG to me, and especially when we're trying to save our future groups time by getting this done without making anyone else wait on us. Please ensure this mechanic remains available for use while the instance is open so that the achievement is not blocked.
(Also, you already have an achievement named High Flyer, for grappling in Vateshran. Since both achievement names refer to the same idea, of someone flying, the difference in spelling between Flier and Flyer is inconsistent, arbitrary, and confusing. I suggest one be renamed.)