Basically, after working with TurboTax support, the solution is a kludge. (delete all contributions to charity data in the forms to just leave one entry with $600 for filing jointly in my case).
This should be a concern as the whole purpose of entering data into the forms is to provide a record of truth in preparing taxes.
My opinion is that the software should have calculated the result properly into the 12b box correctly based upon the rule of a limitation of either $300 or $600 (even if the pre-populated contributions within the forms exceeded that amount).
