On Prerelease-5, if you try and jump onto a pathway block, the game tried to push you off it, as if there is an entity on the block. This bug doesn't occur if you simply walk over a pathway, but if you jump onto it from a lower block, or use a slab to walk up to the pathway block, you're pushed off. This does not occur with other semi blocks like chest or enchantment tables. I've attached a video example.