Yes, Reach out to Chevy customer assistance number in your owner's manual. If your dealer can't fix it GM will refer you to another dealer and make arrangements. GM has a national technical assistance center to help dealers with difficult repairs. Some dealer techs don't fully utilize it.
Independent shops do not have this luxury of a shared national database or access to the engineers who designed these systems.
As a retired field tech. of 46 yrs. experience, I know that the factory backed tech as the most resources to solve an unusual issue IF they choose to use them.