Allot of returns for 2020 were processed late, so that cause the original AGI to be rejected. Try using a zero for your 2020 AGI, to see if you can then e-file.
How do I find last year's AGI?
https://ttlc.intuit.com/community/agi/help/how-do-i-find-last-year-s-agi/00/25947
