Now I understand the issue, it's the fact that the amount on line 12 of the IRA Deduction Worksheet does not reflect the amount that is on Form 1040 line 11. If the amount on line 12 of the IRA Deduction Worksheet reflected the amount on Form 1040 line 11, you would get a deduction for the traditional IRA contribution.
I agree, I see nothing regarding the calculation of MAGI for the purpose of a deduction for traditional IRA contribution that says to add back the taxable amount of the CRD. However, the IRS has not yet released 2020 Pubs 590-A and 590-B, so it's possible that these will include this modification and the TurboTax developers have some advance notice of something about this. Still, the behavior should be no different that with regard to the treatment of disaster distributions on other Forms 8915, so it seems that the treatment of a CRD on From 8915-E would be done no differently.
However, not adding the total taxable amount of the CRD to the amount on line 11 would produce a calculation loop, so maybe this is the method that is used to break that loop. I think that macuser_22 mentioned something like this earlier.
