Bug, with non-working mode to sit down.
This bug has been present since the release of the sneak mode in 1.5 blocks; And is still present in 1.20.10.23.
The video shows:
1-When you're in gamemode 1, you can't sit down.(Therefore, it is not possible to go through 1.5 blocks, and for example put a block next to the hatch, without interacting without a hatch).
2-When you're in any gamemode, and you're in the water, you can't squat either.(Exactly the same examples as in 1 situation).