Problem with quick cast/ smart cast

I used to always have quickcast on my computer and had special bindings because of my mouse with out any problems, but now i got a new mouse and reset the bindings to default. After turning quickcast back on, it made it so it casts spells on button release instead of on the time it was pressed. I know this is only a difference of a small fraction of a second but it makes a difference when you main and cant land a single bola while jumping