The player can fall off a block while sneaking when walking into bamboo in certain situations

If you are sneaking on top of a block and walk into bamboo that has a gap big enough to fit a player, you will fall off. However, the bug seems to only occur in certain situations.

Steps to Reproduce:

  1. Create a setup where you have a block, like dirt, next to bamboo. The bamboo needs to be on the far end from the block, so that there is a hole big enough to fit a player. The bamboo also needs to be taller than the block.
  2. Stand on top of the block and sneak.
  3. Walk towards the bamboo.

For those who do not wish to find a sufficiently off-center bamboo shoot via trial and error, this comment provides a seed and coordinates where the issue occurs.

Observed Results:

You will fall off the block.

Expected Results:

You wouldn't fall off the block.

Notes:

The bug does not seem to occur if you are standing on bamboo, as in MC-160723. The bug also doesn't seem to occur if the bamboo is level with the block. The bug also seems to be present in Bedrock (MCPE-64930). Also, make sure that the gap between the block and the bamboo is the right size (see: no_gap.mp4). I have confirmed the bug on both 1.17.1 and 1.18 pre-release 5.