Bug Report - Review Stage changes charitable deductions

I have completed my federal and state returns.  Both passed their individual review/error check with no errors.

My return utilizes the standard deduction with an additional $600 deduction for charitable donations (filing jointly).  

When I get to the final review stage "Let's make sure your taxes are correct" and "give us a minute to Look things over" I noticed that my federal tax due suddenly jumped up.  It then tells me that there is one area that needs review.  

When I continue it opens up the 1040 Wks and flags line12b "charitable contributions if you take the standard deduction" as having an unacceptable value.  Sure enough it is $300, when it should be $600 for filing jointly.

I manually type $600.  The tax due drops and all is well again.  Re-running the Smart Check as prompted works  yields no errors.

HOWEVER, if I stop and start the final review process again, the loop repeats.  TT changes $600 to $300, increases tax due, and  then flags the $300 in error.