Hovering on soul sand bubbles then heading off can sometimes count as fall damage

The bug

I was hovering over soul sand bubbles while making a bug report, to then find myself dying when i went to get off of the bubbles which is next to land in a 3x2 tunnel and taking massive fall damage. Insta-death. Does not work every time, seems to only work if you can get off of the bubbles while still in the air.

How to reproduce

1. Make a 3x3 of bubble columns
2. Give yourself an elytra
3. Look straight down
4. Teleport yourself 1000 blocks up
5. Press space
6. Wait a bit
   → Once you hit the bubble columns, you die