Inconsistent fall damage when mobs land in water

When mobs are dropped into water through a 1x1 tunnel the damage that is sustained on impact is seemingly random depending on height. 

To recreate:
Build a vertical 1x1 shaft

Place water at the bottom

Spawn mobs at different heights and see if they take damage

 

Video: Minecraft 2023-10-01 13-11-54.mp4