Odd chance where you take fall damage when sprinting off 2 or 1 blocks

Sometimes when you sprint off 1 or 2 blocks, you randomly take 1-3 hearts of damage.

What I expected to happen was...:
Not take any fall damage.

What actually happened was...:
I took fall damage.

Steps to Reproduce:

1. Find a 2 or 1 block drop
2. Sprint off
3. Try again if it doesn't work

(No proof sorry I can't record)