2020 Return was rejected

Just tried to file my 2020 return.  It was immediately rejected.  It stated that either my SS# didn't match or the IRS had already accepted a return for that SS# (which it hasn't - I checked the IRS.gov site).  The exact text is below**.   I wonder if the problem has to do with the fact that my 2019 AMENDED RETURN has not been processed yet?  I filed that (by mail) back in March of 2021 and it STILL is in limbo (mail receipt shows they have it).  When I e-filed this 2020 return just today, I entered last year's AGI from the amended return - so I wonder if that may be the problem?  Even though the reject code says nothing about a mismatched AGI.  Should I try again with the AGI from the original return from 2019, since that's the only number the IRS has on file at present?  Any other suggestions?

 

** If "Amended Return" checkbox is not checked, then taxpayer TIN in the Return Header must not be the same as a TIN of a previously accepted electronic return for the return type and tax period indicated in the tax return. This return was rejected by the IRS bec ause the taxpayer's id number assigned to this return has already been filed and accepted by the IRS> Please verify that you have accurately entered the taxpayer's SSN or TIN and make corrections if required. If no errors have bene made in the entry of the taxpayer's SSN it may be necessary to contact the IRS... (yeah right, impossible to get a person, I've tried numerous times to find out about my amended return).