Boats acting like a slime block

I was playing regular survival when I tried to get out of a boat into my house, and I jumped on the boat a few times and when I landed I took fall damage. It was like jumping on a slime block and jumping off.

What I expected to happen: No fall damage since it doesn't appear like I was gaining height while jumping.

What actually happened: I jumped off the boat and lost 2 and a half hearts with full iron armor, despite the platform I landed on being right next to me.

Steps to reproduce: (video here: https://vimeo.com/343721024

1. Put a boat in water
2. Build a platform right next to the boat made of a solid block (no water, slime blocks etc)
3. Jump on the boat a couple times
4. Jump off of the boat onto the platform, and fall damage should be taken