Steps to reproduce the issue
Grab a block, then build a vertical tower
And when destroyed the block, move near close to the end of the block.
Expected result
When is destroyed the block you cannot falling close to the end of the block
Actual result
When is destroyed the block you can falling close to the end of the block.
Attachments
Comments 3

The function of crouch/sneak preventing you from moving off of the edge of a block only works when you are on a block. When you break the block underneath of you, you are no longer standing on a block. Therefore, you can move farther, past the edge of the next block down. Players have always been above to move horizontally while in the air in Minecraft. This is not a bug.