The contact keyframe on the zlocation seems to be set to Bezier interpolation and Aligned handle type. So when you look at the handles, the left one is pointing up toward the parabola, which is good. The handle on the right is pointing down. For now its fine but as as soon as you place a new key frame the Bezier curve is going to cause an overshoot in order to connect between the keyframes. Which is what you’re seeing. An easy fix to this would be to press “v” and change the handle type to “free”. This way you’ll have control over how it eases in and out.
Another fix would be to set the handle type to automatic, you could then scale the handles in when you need a sharp curve.
