Ball Bounciness problem

Hey, I'm using Physics 2D Material to jump a ball over a ground. I set friction to 0 and bounciness to 1, then I added a Rigidbody 2D to the ball. Here's the problem, when the ball is jumping, it's get higher and higher, but I want the ball just jump always at the same hight where I released it. How can I do it?

I added a picture for clarity