Did you mail federal to the IRS Treasury Dept separate from your state return? They go to different places. Some people have been mailing both federal and state in the same envelope. The IRS is probably still behind processing mailed returns for 2019. Call the IRS and ask. If they didn't get 2019 you will have to mail it again.
And when you file 2020, if the AGI rejects, try using 0 for the AGI since they haven't processed 2019 yet.
