The last several yamato games I've played (~1 week), there have been numerous instances of flying slash casting and going on cooldown without yamato moving at all. The animation may start but then it's immediately cancelled. I don't believe I am cancelling it via key press, but it's possible that some other input besides space is cancelling the ability since I usually hold right click immediately after.
This bug usually happens when I try to flying slash someone under a guardian/walker, or if someone runs around a corner it may cancel after casting. Here are match IDs I've seen it happen:
69623030 (I remember once around a walker it was cancelled and once around a wall while on the enemy side blue lane)
68852744 (a couple times under tower in laning stage when cast on vindicta)
This bug usually happens when I try to flying slash someone under a guardian/walker, or if someone runs around a corner it may cancel after casting. Here are match IDs I've seen it happen:
69623030 (I remember once around a walker it was cancelled and once around a wall while on the enemy side blue lane)
68852744 (a couple times under tower in laning stage when cast on vindicta)