The solution might be to prepare a substitute 1099-R on Form 4852 on your amended 2019 return.
To do this in TurboTax, go to the 1099-R section of your 2019 amended return and check "Add another 1099-R." Then, on the screen headed "Tell Us Which 1099-R You Have", check "I need to prepare a Substitute 1099-R". Then follow the screen prompts, but change the Box 7 distribution code to "8 - return of contribution taxable in 2019." The program will prompt you to enter an explanatory note.
Then, submit the amended return with the Substitute 1099-R, not the original.
@DoninGA -- any thoughts?
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
