Walls are acting as if there is a block above them when placing them underwater.

Put the summary of the bug you're having here

What I expected to happen was...:
The walls would act like they normally would if you put 3+ in a line with no blocks on top of them.

What actually happened was...:
The walls acted as if there was a block on top of them no matter how many of them were in the line.

Steps to Reproduce:
1. Place walls underwater with at least 1 layer of water above them.