Do you have a high overscan setting on the fill
Double click the layer and on fill mode check the overscan
if for example you set a 5% overscan on a 100x100 box that will be 5mm
So if your origin is at 0x0 and machine trys to ovescan 5% to the LEFT of zero it will for SURE cause issue
I am not 100% sure however if lightburn has built in procedures to avoid this @LightBurn
You can always judge the box in 5mm and verify if the problem disapears?