Unity 2D Physics Material 2D issue bounciness

Question

I'm a beginner and I'm trying to make a simple game: Pong.
I've used the physics material with 0 friction and 1 bounciness for the ball, so I don't have to make every collision by code.
The problem is the following: if the ball has a low degree angle and hit the ground (or the ceiling), the ball will start move only horizontally and stop to bounce. Why dodes this happen?

Here is a little gif with the problem:

Thanks! Ask me anything if needed

Answer 1

In the physics 2D settings under Edit > Project Settings > Physics2D

Reduce the

Velocity Threshold

Set the threshold for elastic collisions . Unity treats collisions with a relative velocity lower than this value as inelastic collisions (that is, the colliding GameObjects do not bounce off each other).

If your angle is very flat the relative velocity for the collision impact is very small as well.