I have a simple 3d .obj viewer. The resulting 3d image is distorted along z axis Distorted along z axis.

I’m using a lefthanded coordinate system with a lefthanded perspective projection matrix. Best I can tell the frustum settings are correct, as is the matrix design. I’ve provided a screenshot to show the issue. 2 textured cubes, one center screen, one translated to the right by 5. the one on the right shows distortion along the z. Not sure what I’m missing.