Physics Problem :Collision(When ball moves from one ground (made of cube) to another )

@aldonaletto Hello I am making endless game In which ball is main player And the problem is that when the ball step in another ground It automaically satart to bounce even the ground is alligned perfectly.Please help me I am seeking for this solution for about more than one month . I am waiting for your reply .And my problem is same as in this video but my Main player is ball :https://www.youtube.com/watch?v=rm8IWL0vJgA. Hope you have appropriate solution.