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Thanks.  Here's a follow up question:

I filed my 2019 return BY MAIL in July 2020 (they extended the filing date until July 15th)...... and now it's almost 9 months later...... would they still not have processed it?  The transcript says "No tax return filed" and yet they DO acknowledge my payment check with my return.  (How can that be??)

I ask this because on the IRS website, they note (in the "Retiree & Senior Citizen" section) that returns filed by mail are taking longer, and they say I should NOT file a 2nd time.  So..... should I?  or shouldn't I send them a copy?