Problem with alignment shifted and lined partially offset?

I’m using a Boss 14x20 CO2 Laser. I keep having this issue from time to time and never know when or why the cutout lines shift partially thru the program. In this case the upper half turned out correct and the lower half are trashed. Preview always look correct. I even have the entire drawing grouped.

Did you ever get this figured out?

Never got it figured out. Just rans smaller number of parts and all went fine. I’ll play with it next time it shows up.