What you say cannot be done.
You cannot "roll" an excess 2020 Roth contribution at all. You CAN recharacterize to a Traditional IRA contribution instead of a Roth contribution that is treated as if the Roth contribution never happened and it was a Traditional IRA contribution in the first place.
However, if that was done after July 15, 2020 (you say it was done in Sept) then it was too late to contribute to ANY 2019 IRA. It could ONLY be recharactorized as a 2020 Traditional IRA contribution that will be reported on your 2020 tax return next year.
Per IRS Pub 590A https://www.irs.gov/publications/p590a#norecharacterizationsofconversionsm-550dcfb7
Recharacterizing excess contributions.
You can recharacterize only actual contributions. If you are applying excess contributions for prior years as current contributions, you can recharacterize them only if the recharacterization would still be timely with respect to the tax year for which the applied contributions were actually made.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
