I believe there is a bug in the Jump action though, specifically regarding the opposite force applied to the floor. There you set the ground sensor’s hit normal as the position, which seems erratic. My suggestion is to change it to the ground sensor’s hit frame position instead, like so:
the variable only gets the value of the property, so it can’t change the property’s value directly, you’d have to write it like this, which would make it longer than just leaving it how it was.