There may be some withholding limitations, its generally with state withholding that Ive seen.   It would be unusual for withholding to be so high and may look like a fraudulent amount or a typo mistake so EFiling may not be allowed, even if its legit.

Have you entered a 1099R and input high withholding and it tells you no Efiling is allowed?  I tried it in a 2020 dummy return, 20K 1099R with 15K in Fed withholding, I don't see any Efiling errors.