I experienced the same problem with my tax filing for 2020. My wife and I took out investments from the a company years ago on the same date for the same amount, so both have identical annual income. I have reported this investment on my tax forms for numerous years using TurboTax and never experienced a problem with my return being rejected until this year. After making sure that the both investments were attributed properly to each of us with correct identification, I decided to try adding one penny to the value of one of the investments. Within hours I received notification that my 2020 tax return was accepted. I hope that this solution will be of help to others experiencing tax returns being rejected due to seemingly "duplicate" 1099-R forms.
