It has been noted by my guildmates multiple times, but I finally got a glimpse of this bug myself. In the following video clip, taken from my group's Wednesday Cyrodiil raid, you can see me cast Charging Maneuver (Rapids), with the animation clearly showing and stamina consumed but no effect gained or cooldown initiated. Over long time spans, upwards of a minute, I was consistently not able to get Major and Minor Expedition by casting Rapids.
As you can see from the (admittedly often inaccurate) player counter, not particularly many players were around at the time, only my group of 18 and maybe a few friendly PUGs, and no fight was going on that would justify this as input lag. And unlike actual input lag, where the skill doesn't go off to begin with, here Rapids clearly does go off and it even consumes resources without effect.
Here's the clip:
https://www.youtube.com/watch?v=iS08kL2nNp4
Edited by BardInSolitude on October 19, 2022 8:14PM DC loyalist. Ball group afficionado. Bard.