If the player jumped onto a soulsand/farmland/grasspath block, he will seem to stand on the "edge" on the block and be pushed off once stopped attempting to move.

If the total area of soulsand/grasspath blocks is large enough, the player can managed to stand normally on these blocks again by jumping additional 2 times after standing on the "edge". (does not work on farmland due to it being converted into dirt when jumped on)

To reproduce the problem, place one block of soulsand/grasspath/farmland at 1 block higher level than player standing on and jump on it.