This is still an issue. I’m consistently taking massive falling damage when falling into water deep enough for my mounted character to be fully submerged. Namely, the pool in front of the underrot entrance, which is presumably intended precisely to keep players from dying to falling damage when trying to get to the dungeon.
Are you using a water walking mount or a water walking potion/path of frost (a dk in group for example) I say this because if you have anything that is currently up allowing you to waterwalk when you hit the water then it will give you damage just as if you hit the land. Other then that, only other explanation I could think of is you are barely clipping a rock or something.
Nope! Using a regular mount that has no water walking properties.