Fences acting like slabs

When you walk over a fence the fence acts like it has another slab on top of it making the player look like they are floating.

As this has not happened in 1.2.11-1.2.12 etc i have decided to report this as it just doesn't seem right at all. This bug also occurs when in Survival mode.

I have searched and not found anything related to this bug in the bug searches.
Thanks for taking a look at this.