If you already enter the 1099-R as RMD and changing your answer to the RMD question doesn't work then you have to delete and renter the 1099-R form. RMDs were waived for 2020 and you must indicate to TurboTax that none of the distribution was RMD.
Please follow these steps to enter your 1099-R and RMD rollover:
Also, make sure you enter the full amount returned, if you had taxes withheld and did not return the full amount then that part will be taxable.
You can verify your entry by looking at your Form 1040 line 4: