Here’s some instructions I received from support once. Frankly, you might have to wait until the latest development firmware is released as there’s a bug in the calibration that could explain your issues.
In the meantime, just use the center 100mm of printable space and nothing more, it will limit the un-levelness.
If there is something wrong with the hardware you will be best served by creating a support ticket, see here:
https://forum.snapmaker.com/t/laser-module-not-working/19561/2?u=brent113