Slimeblock fall damage

What I expected to happen was...:
I fell from a long distance on slime blockes while holding shift (crough button). I expected that i would not bounce up and not get any fall damage.

What actually happened was...:
I died because of fall damage

Steps to Reproduce:
1. Put a slime block underneath you
2. fly up in the sky
3. change to gamemode survival
4. hold shift while falling