Did a new test last night, remarkable results 
First:
Lightburn file. I believe setup is good, origin also. 48x48 inch.
Second:
This is how it is loaded into MASSO. saved it on a USB as .nc with generate G-code in Lightburn. Look at the position?
Thirt:
this in dry run mode. It follows the path as shown in the second picture.
Fourth:
No dry run. It follows the path as designed in Lightburn.
No soft alarms here. But I have the same issue with a design of 900mm width which gives me a soft alarm on x axis.
So might it have something to do with the way it loads the files into MASSO?