Thanks for the cut and paste I can say that is right for cutting but min power does play a role when doing grayscale images here is a link from another post. I am just trying to point out that my original response was not wrong, min power should be set properly and it is used in grayscale. Perhaps its not the cause of the random lines in this post but its a good start for the poster to set it right and try burning again to see if the issue goes away.
https://forum.lightburnsoftware.com/t/grayscale-engravings-very-light/11181/4?u=renegade1966