(e)=>{scene.my.attraction = scene.my.attraction = 7000}
Is the same as
(e)=>{scene.my.attraction = 7000}
So not wrong it was just programmed differently.
@Xray This is because of the spin of the ball, it happens when you hit with the racket in motion up or down Then the ball spin and when it hits the border it goes to smaller or larger angles depending on the speed and direction of the ball spin, i fixed it changing the frictions thanks for report the issue