space above soul sand blocks/pushes player

Put the summary of the bug you're having here

What I expected to happen was...:

speed should be slowed down when walking on soul sand

What actually happened was...:

when attempting to traverse soul sand you run into an imaginary wall, or it pushes you off

Steps to Reproduce:
1. jump on to a patch of soul sand
2. attempt to walk on to a patch of soul sand
3. ...