Make sure Rotary Mode is not enabled:
With that Off, then verify the Design Units are set to inches rather than millimeters:
And the Control Units are set to mm/s:
https://docs.lightburnsoftware.com/2.1/Reference/DeviceSettings/DimensionsUnits/#control-units
If all that matches, it’s possible the controller has the wrong step size settings:
That’s generally due to a mismatch between the LightBurn Device Origin and the machine controller’s origin: