Laser problems background slightly burned

I suspect you’re experiencing a laser module failure.
Try running some tests to confirm:
1. Create a regular array of filled rectangles and burn. Do you get burns where unexpected and is the pattern irregular?
2. Try running a material test pattern. Does this reveal any pattern of power or speed where the issue occurs?
3. If you have a voltmeter or scope, try testing PWM pins from controller while the job is running. Do you see voltage when unexpected? 0% power will correlate to 0V, 100% will likely correlate to 5V or possibly 3.3V or other depending on your specific hardware, other power levels will have a linear relationship to voltage between 0V and max voltage at 100%. This will tell you if the issue is at the controller or laser module.