TurboTax does not treat code U as being subject to an early distribution penalty regardless of your age.
With a zero on Schedule 1 line 8, no penalties are being assessed on Form 5329.
If you reached age 59½ during the tax year, TurboTax might ask if the distribution was made before or after age 59½, but your answer to this question is irrelevant to a code-U distribution.
