First, make sure your birthdate is correct in the Personal Info section.
For a normal retirement distribution, you should see Code 7 in Box 7 of your 1099-R.
If you're using TurboTax Online, clear your Cache and Cookies and return to the 1099-R entry area.
If you imported your 1099-R, you may delete/re-enter manually.
You can also Delete Form 5329; however it may regenerate if the 1099-R (or birthdate) are incorrectly entered.
Since we can't see your return in this forum, let us know if this resolved your issue. You can also Contact TurboTax Support.