Put the summary of the bug you're having here

What I thought would happen is that I would easily sneak down a block.

What actually happened is that when I tried to sneak down a block, I simply could not. It froze until I got out of sneak mode and then I could go down a block.

Steps to Reproduce:
1. Find a hill
2. Go into sneak mode
3. Make sure there is a block 1 block under you. Try going down it well still in sneak mode. As you can see it makes it so that it stops you from doing it.