As can be seen in the video below when the block at the bottom of the water column is changed from a magma block to soul sand, there is an update period for the column of water to switch between pull and push. This results in a jittery motion where the player is at the top of the push column as the rest of the blocks above are being updated.

This has also been replicated on Windows 10 and a realm with an X-Box player experiencing the same issue.