The bug

Falling onto hay bale or a honey block reduces fall damage. But falling onto a target block does not, even though it's logically made of hay bale which also reduces fall damage.

How to reproduce

1. Set gamemode to survival and place hay bale/ honey block below you
2. Run

    /tp @s ~ ~100 ~ 

   → After falling onto hay bale/ a honey block, you are left with half a heart.

3. Run the command again, but instead place targets below you
   → The message "[player] fell from a high place" is displayed.