Two things so far:
Cannot swim along the surface high enough to breath air. Instead, the player goes from swimming position to standing position once air-level is reached. Swimming should still be possible while swimming at the surface, just high enough to breath air.
Also, swimming up to a block will cause the player to go into the standing position once the player is touching it. This makes swimming into 1x1 holes difficult.
Until now, i thought this was a 1.21.4 bug in minecraft but i ran the client in vanilla and everything is normal. Then I tested this without any other mods present on 54.0.26 to be sure. This has been occurring since at least 54.0.6.
Thank you.
Edit: fixed a typo
