Hi everyone. I did the steps slightly different than the solution that's been posted here so I figured I'd share as well. This worked for me...
1. Start that section again and UNCHECK the coronavirus box. Then on the next screen I picked a random disaster and then went through the rest of the questions.
2. Go back to the beginning and go through the questions again. Leave the coronavirus box unchecked... but instead of picking a random disaster, choose the very top option in the dropdown list which is blank. This will delete the code TurboTax is putting on Line C.
3. Go back to the beginning and go through the questions again but this time check the coronavirus box.
I was able to submit to the IRS after doing this. I got an email shortly after that it was accepted.
