Why is TurboTax refusing to e-file my amended 2020 tax return?

[Aarondhp24]

I need my taxes amended in a timely manner for reasons I won't go into here. I e-filed my 2020 and 2021 returns. I successfully amended my 2021 return an e-filed it. When I went back to amend my 2020 return the only option it gives me is to print it out and mail it in. The amendments were identical in almost every conceivable way. There was no change to my tax liability or refund in either case. Why is TurboTax allowing me to e-file my 2021 amended return, but not my 2020 amended return?

[Bsch4477]

Simple answer is that TurboTax doesn’t provide that service. 

[rjs]

TurboTax does not support e-filing of past-year returns, either original or amended.