CNC Bed suddenly not level

Been CNC fine since I got machine. today, I went to engrave words on a board and the cut depths decrease as the X axis increases. What could possibly caused this? I have not mashed the plate nor moved device. Tested on two boards so it is not a flatness issue

Did you mount your X linear module one hole diagonally?

I am not sure i understand. It looks to be assembled correctly and in the same holes on each side. I am not seeing how I would mount with one hole diagonally. If this is one of those “easy to f-up” steps that occur every now and then with Snapmaker, I probably did screw something up.

Dont know the artisan, so you have to check if you assembled right.
Maybe firmware reset with M502 in the console and M500 for saving helps (this did so by people who where too near to the bed with the 3dp toolhead).

If this doesnt help, you have to reach out to support…