After you file

You started out saying 

I submitted both state and federal returns on time. 

Then you said,

As of yesterday, I tried to submit my 2020 taxes and found out through IRS.GOV that the Fed says I did not submit my federal return.  

You can't amend a return that has not been filed, so check the status of your returns by following the instructions here.     

Although state returns can be e-filed with your federal return (or after your federal return has already been accepted), it's no longer possible to e-file state returns before the federal.

This adds an extra layer of security to all e-filed state returns. This also means you won't be able to e-file your state if your federal return was, or will be, paper-filed.   

If you are using Online software, you can sign in - you will and on the Tax Home page.  Scroll all the way to the bottom and review the Your Tax Returns section to see the details of all of your returns.

If you are using Desktop software, click on Forms in the upper right corner to see every form included with your tax return.   Federal forms are listed first and then state return forms are below the federal list.     @MunwelDaJenius

Also, this is an old thread that may not get many eyes on it, so if you are still having issues, use this link to start a new discussion.   More community users will see it so more help will be available.