Nothing that you described explains why you received a code R 2020 Form 1099-R. A code R Form 1099-R reports a recharacterization in 2020 of a traditional IRA contribution made for 2019 to be a Roth IRA contribution instead or a Roth IRA contribution made for 2019 to be a traditional IRA contribution instead. It has nothing to do with tax withholding, any regular distribution or any RMD. A code R Form 1099-R cannot show any tax withholding in either box 4 or in the withholding boxes for state and local taxes.
