Bowing on Z axis problem

I have an Ender 3 Max with Klipper, and an Elegoo Neptune 4 Max with Klipper, and the same exact problem on both machines, so the only connection is Orcaslicer. I've done the pressure Advance tests, and both machines are set up with the box print.

However... Whenever I print ANYTHING that is square, rectangular, etc, the Z walls on opposite ends are ALWAYS bowed - badly. It rounds it off and bows it in the middle. Anyone have any suggestions?