When landing in water from an Elytra flight no matter your velocity your elytra never deactivates and enters a bugged state where you can't swim normally unless you touch the bottom of the water (a block other than water). I've seen people moaning about this in other versions but I haven't tested in any other versions other than 1.20.1, 1.20.3, 1.20.4. Not sure if this is intentional but I don't remember it in past versions.

Replication:

There has been no time where I have landed in water in 1.20.4 and this hasn't happened