Sprite Flipping on Camera Move - 2D

I'm working on a top down 2D game and I'm having a strange problem. When I move my camera, some of my sprites appear to flip along the vertical axis. Take a look at what I mean. Notice how the wood texture has the darker vertical lines on the right side. Now I move my player over a few blocks right and the darker lines vertical lines are on the left. Is this a weird unity lighting thing? Or perhaps a floating point rounding error going on somewhere? ( maybe with even vs odd positioned tiles )

Any help is greatly appreciated. Thanks.