The Form 1099-R seems wrong. A corrective distribution of excess elective deferrals from an individual 401(k) should never have a code 1 in box 7. Is the IRA/SEP/SIMPLE box marked on the Form 1099-R that you received? If this was a distribution from an individual 401(k) as you previously stated, the IRA/SEP/SIMPLE box should not be marked. However, the reporting on the Form 1099-R that is inconsistent with a corrective distribution from an individual 401(k) is making me question that.
I had expected that you would either receive two Forms 1099-R, one with code P and $2,000 in boxes 1 and 2a and the other with code 8 with $100 in boxes 1 and 2a, or a single code 8 Form 1099-R with $2,100 in box 1 and $100 in box 2a. In the case of the single code 8 Form 1099-R with $2,100 in box 1 and $100 in box 2a, you would separately report the $2,000 as taxable on on your 2019 tax return by entering it into 2019 TurboTax as Miscellaneous income not already reported on a W-2 or 1099-R, which is apparently what you have already done.
Some of the information provided to you the TT CPA is irrelevant or just wrong. The reference provided by the TT CPA applies to distributions of excess elective deferrals after the due date of your 2019 tax return, July 15, 2020 (extended from April 15, 2020 by the COVID-19 disaster declaration) under the EPCRS, which would be reported with code E in box 7 of the Form 1099-R. That has nothing to do with your situation.
