Endermen teleport to waterlogged blocks, although they shouldn't

Endermen usually do not teleport to any waterlogged blocks, to avoid teleporting into water.

But there is a case where they do.
https://www.youtube.com/watch?v=Ad8H2UvYR54&feature=youtu.be

 

Steps to reproduce:
1. Open a void world, or go to the end and fly away from the end islands.

2. Make a plattform of waterlogged blocks, with a full surface that are movement-blocking [see comment from 6th April 2021]
(For example waterlogged top slabs: /fill ~ ~ ~10 ~ ~ ~10 minecraft:smooth_stone_slab[type=top,waterlogged=true]

2.1 Light up the platform of slabs, to stop endermen from spawning on it

3. Make another platform of any full block only a few blocks away. (/fill ~ ~ ~ ~10 ~ ~10 minecraft:smooth_stone)

4. Summon endermen on the second platform, for example with a repeating command block in the middle a few blocks above.
(/summon minecraft:enderman ~ ~-4 ~)

Note how none of the endermen teleport to the platform of waterlogged top slabs!

Then:

5. Make a ceiling at least 3 blocks (and maximum 20, so best something like 5) above the waterlogged top slabs -> The endermen will, as expected, teleport to the ceiling (/fill ~ ~ ~ ~10 ~ ~10 minecraft:smooth_stone)

6. Cover the ceiling in water (/fill ~ ~ ~ ~10 ~ ~10 minecraft:water)

NOTE: Now endermen will teleport to the platform of waterlogged slabs!!!

See video for an example of the setup: endermen tp although they shouldn't - YouTube