Polished Cinnabar stairs texture gets displayed wrong on back of 3 quarter stairs

If you are facing in the negative x direction and place a 3 quarter polished cinnabar stair with its back faces facing towards the negative x and positive z directions there will be a line in the middle of the positive z face. The same thing happens when you place a cinnabar stair at a perpendicular angle to another polished cinnabar stair to create a 3 quarter stair the line will appear on the back face of the 3 quarter stair in the direction you are facing.