I have a problem with my laser when placing a figure horizontally and when placing it vertically, the same figure when cut is two or three millimeters too long.
Easiest to fix that is to cut a square out of plain paper, example 200mm x 200mm.
Mark the X & Y axis to not prevent switching it when you remove the cut square.
Measure the X & Y axis. There should be a difference.
Go to lightburn “Edit → Machine setting” and correct the calibration. Enter that you expected 200mm, and what was actually cut.
Cut another 200mm x 200mm square and measure again.
Also make sure the new square is actually a square. If you rotate the cut square by 90 degrees, it should still fit the area it came from exactly. If the square does not have 90 degree angles, then your laser’s X-axis and Y-axis are not forming a 90 degree angle. You have to adjust one side to make sure X-Y movement is at 90 degree angle.