Need Help! Mill jumping but LinuxCNC shows correct path

I am trying to cut a 3d part.

I setup, home and touchoff the part. Start running the program and everything looks great for 3 complete passes of the code. Once it gets to the 4th pass .003 into the part the mill the jumps to a different spot on the material ruining the part. It jumps to the same spot each time but Axis shows the correct spot on the material.

I have tried this using 2 different tool paths generated by 2 different CAM apps (MeshCAM and HEEKS)

I have tried:
G92.1
G54
G49
running relative coordinate display

And I get the same behavior each time I attempt to cut this part.

Any help would be HUGE!!!

Many thanks,

The Wazz