Here’s how to post code on the forums: Using code tags properly
I’m not going to be able to debug all that although looking through it I don’t see anything obvious. Have you tried to simply add a Rigidbody2D and collider and let it bounce up/down without all this script? Or just move a SpriteRenderer via its Transform? That will discount anything you’re doing in the above script. You need to narrow down your problem.
As I asked previously, interpolation on the Rigidbody2D? This should be the first thing you try; it’s for visual smoothing because physics (by default) doesn’t run per-frame.