I received a similar notice about my 2019 tax return just one month ago. I submitted electronivcally through Tubo Tax, but the IRS claims they never received it. There's no means of contacting them. I've tried via phone. They won't answer. I've tried online but my account will lockout for 24 hours if I attempt to use it.
They want me to resend my 2019 return or lose a potential $9,900 in credit.
