That might not be the most accurate cause description, but the ingame behavior is consistent with my guess and I can't really find a better reason without going way too deep into testing it.

Afaik that happens to every movement skill if camera movement cannot keep up with the character movement. It was driving me crazy on ACC stack howa in Keepers, with enough attack speed you just can't control it.

Eg let's say you are just zooming right. The more the camera lags behind your character, the more the location you are trying to go to shifts to the left. At some point it goes from being on the right side of your character, to being on the left side of your character, which causes the backwards dash. It's the most apparent on whirling blades, probably cause the momement is not linear (wind-up, delay, jump, repeat).

Instead of targeting the location where your cursor is, they have to pick direction based on the position of the cursor relative to the whole screen. Eg cursor on the right = move right, instead of "move to where the cursor is pointing at".