Artisan 10W laser changing output power during cutting jobs

I have the problem with my new Artisan 10W laser that during cutting jobs the laser changed the output power from time to time. This leads in uncutted areas. Any idea why and how to fix? Is the laser fault or do you know any other reason why this could happen? I did also some video recording where you can see the power change during cutting but unfortunately I am not allowed to upload files as a new user.

Have you tried with a different project? Maybe something simple like a couple of lines? It may come from the piece and/or the gcode generated. You may also look at the gcode to see if there are lines that change the laser power.