You say the size is wrong, but that’s not specific enough. If you create a 50mm circle and burn it, and then change it to 25mm, does it not change at all? Or does the new one come out half the size of the old one, but both sizes are incorrect? If it’s that, it just means your steps aren’t properly calibrated.
LightBurn sends GCode commands in mm or inches, depending on which mode you set, and the controller changes those numbers into actual steps based on the steps/mm settings in the firmware.
This might help: