4x2 Painting (Fighter) improper placement

When trying to place the 4x2 painting down it seems to be checking the wrong blocks to determine whether or not the placement is valid.

What I expected to happen was...:
I have a 4x2 wall of cobblestone, and when placing paintings down the 4x2 painting should cover the entire wall.

What actually happened was...:
Either the painting hangs off of the wall and stays placed down, or the painting covers the entire wall but breaks after about 5 seconds.

Steps to Reproduce:
1. Build a wall of some material 4 blocks by 2 blocks.
2. Either place a million paintings or use the /summon command to summon the Fighter painting.
3. Observe