cannot walk on grass paths

This seems to happen especially on a hill, so create a path using path blocks that changes elevation, and put slab down at the height changes so that you can walk smoothly without auto jump. In my game, I cannot walk up the path. It's as if there is a ghost block there. I can jump onto the path; however, I then "slide" off of the block as if there is something pushing me. So far, I have only had this issue when changing elevation. Up or down works, but up is worse.