As a final update, I rechecked the on-line IRS site today and see the 2021 transcript has been posted. I then looked at my 2021 Turbo Tax software, which still says the IRS rejected my submission. This is further validation that there is glitch in the desktop software, most likely as the result of entering "0" when the 2020 tax filing hasn't been processed. However, surprisingly, I also see that my 2020 filing has been processed in the last week and my transcript is now shown.
