It's happening only with RigidBody when i pushing it up, but when i push it in other directions it's okay. Why? Here's code and rigid body setup
Probably precision error in combination with the gravity calculation fighting the collision. Just a guess tho.
As a workaround, you can increase Physics Fps in the Project Settings to make this less noticeable. Note that you will get visible jittering until you install, enable and configure lawnjelly's smoothing-addon to get physics interpolation.
