Dimension calibration

Basic Information:

Printer Model: ender 3 max
MCU / Printerboard: 4.2.2.

Describe your issue:

Hi Everybody,
I have an ender 3 max that was very accurate and worked really well.
I upgraded to klipper for. speed reasons.
suddenly all my prints are too small and screw don’t fit anymore.
I printed a calibration cube to test how far off I am.
a 20 by 20 by 20 cube came out
X: 18.00
Y: 18.00
Z 18.40

In klipper I don’t have steps to calibrate. instead “rotation distance” and “micro steps”.
I looked online and everyone is saying not to change these values.
Is there something better for me to fix?
for a test I trying changing my x and y rotation from 40 to 36.
but not in the calibration the axis move too much and the ABL calibration is out side the bed area.
what else could be the issue and I can try fixing?
it’s not belts or anything in the printer witch was very accurate running marlin.
Thanks

See Dimensional accuracy problem for a lengthy discussion on the subject.

IMO, you have some mechanical issues or slicing issues (e.g. severe under-extrusion) if you fall 2mm short.