How to reproduce:
Have 4 command blocks,

First:        effect give player levitation 1 120 true        (with button attached to activate).
1 tick redstone repeater delay
Second:   effect clear player levitation
3 tick redstone repeater delay
Third:      effect give player levitation 1 130 true
1 tick redstone repeater delay
Fourth:    effect clear player levitation

Press the button to activate these command blocks in survival, and the bounce from fall damage should be about equal to the height first gained from levitation.

I believe the intended functionality is for there to be no bounce.

Upon further testing, it appears that the player's data value Motion[1] is incorrectly equal to a large positive value after a powerful downward levitation ends.