Fall Damage Bug (send wrong packages)

Put the summary of the bug you're having here

What I expected to happen was...:
The player should take fall damage 

What actually happened was...:
The player sends wrong packets to the server and does not get fall damage

Steps to Reproduce:
1. A player jumps down from far above
2. Just before the ground, 0.5 blocks approximately, the player presses spacebar and resets his Fall Distance and gets no Fall Damage 

or:

1.  A player jumps down from far above
2. The player then immediately sprints forward and presses spacebar
3. Just before the ground, again about 0.5 blocks before, he then sneaks and gets no fall damage (fall distance is reset again)

Here is a video from a German YouTuber: https://youtu.be/q7cTwnCeImY