[Bug] Unrelenting Assault (Revenant Sword 3) delaying/not working at all

Hey,ever since the most recent patch I've been noticing some weird behavior on Unrelenting Assault,in which it has a long delay AFTER the actual cast time of the ability, where I'm already in that "mist form" effectand nothing happens.About 1 second after the ACTUAL CAST there is like a 50% chance for the ability to either work OR not going off at allbut instead going on full CD.

I'm not quite sure if its some weird, not intended, behavior with quickness or not'cause I've been running the Song of the mist trait, which gives me quickness,whenever I switch to Shiro and hit someone with it (which is part of my burst rotation in pvp/wvw).

It goes as follows:

Starting off in glint legend -> Sword 2 and right before the projectiles are about to hit switch to Shiro -> Casting Sword 3 -> Getting a delay of about 1 sec after the cast in which I can't do anything but move -> cast goes off/cast doesn't go off but on full CD

I hope someone sees that, cause it's quite a gamebreaking or rather game disrupting bug for me as a power revand doesn't help the already quite weak class at all.

Thanks.