Thank you to @DanaB27, @dmertz and @fanfare for their additional expertise.
I managed to find someone at Fidelity who could see they issued this 1099R. The overage occurred sometime in calendar year 2022. However I was only issued a check for the overage amount in calendar 2023, which (according to them) is the relevant date for taxes, so apparently I can just list it as other income/over contribution on this current year's taxes despite the P code.
