I had the same problem. Here's what worked for me:
- Go to Review.
- When you get to the screen titled Just one more step and we'll file your returns select Get ready to save and file your returns.
- On the next screen (Let’s get ready to e-file) choose File By Mail. (Makes no sense, I know.)
- Next to your state return on the next screen, select Change then on the following screen I'm not ready to file.
- The next screen will list just your 2020 Federal return and you can go on to file your Federal return.
