"For line 5 page 28 first paragraph middle column……"
@VolvoGirl , there is certainly ambiguity in the IRS instructions for lines 4a/4b and 5a/5b. There always has been. I believe that "don't make an entry on line 5a" would only apply if all distributions being reported were entirely taxable on line 5b. Once you have an need to make an entry on line 5a for a distribution that is not fully taxable, I believe that one must include all gross amounts on line 5a. "Don't make an entry on line 5a" is is not the same as "don't include the amount on line 5a." "Don't make an entry on line 5a" implies leaving line 5a blank, which cannot be done if some distributions are only partially taxable. The similar case of lines 4a and 4b has an instruction to include all amounts on line 4a if multiple distributions are reportable on lines 4a/4b.
The IRS instructions should have been written to simply require the gross amounts of all distributions to be included on either line 4a or 5a, eliminating convoluted instructions regarding when and when not to populate those lines.
As to how TurboTax developers interpreted the instructions, it's entirely possible that they chose to omit from line 5a any amounts that come from distributions that are fully taxable, but that makes whatever is shown on line 5a rather less useful since one cannot use it in conjunction with the amount on line 5b to determine the nontaxable amount being reported on the tax return.
