Thanks to @dstarke for posting the tech support manual. Pages 24 to 25 describes how to fix this issue. (I couldn’t find the option to manually set the laser height)
Now back to a reasonable height
Laser Calibration Fails
If the Laser Calibration doesn’t go well, the Touchscreen will display Failed.
Possible Causes• The laser is too high.
Actions
Two options are available.
Redo auto focus. Tap Failed, slide the scale left to select the leftmost line, and tap Save. The screen should go back to the main menu. Tap Calibration. If the problem persists, repeat the steps until calibration succeeds.
Change the Laser Height manually. On the Touchscreen, tap Failed > Settings > Laser > Adjust Laser Height. Set the Laser Height to 23.0mm and then recalibrate. If the Touchscreen keeps showing Failed, and several lines fail to be burned, then lower the laser height (to 21.5 mm or 19 mm, for example), and try again.