Is the preparer the Third Party Designee?  If so, Schedule 6 should not be filed.

From the 1040 Instructions:

If you want your paid preparer to be your third party designee, check the "3rd Party Designee" box on page 1 of Form 1040. Do not complete Schedule 6.

https://www.irs.gov/instructions/i1040gi#idm139844914767456