401(k) Conversion of after tax only contributions

Situation:

- In 2020 I made after tax contributions to my 401(k).

- Those after tax contributions had some gains throughout the year.

- At year end 2020, I converted those after tax fund AND associated gains to a Roth IRA.

- 1099-R correctly shows the distribution type as G, shows the cap gains portion in box 2a, and the amount of after tax contributions in box 5.

- Note box 3 is empty.

 

Question:

Since this is all after tax funds and associated cap gains, I would expect the cap gains (box 2a) to be taxed at the cap gains rate and NOT at the income rate. Am I mistaken or am I incorrectly characterizing this in Turbo Tax (which is currently applying the income rate)?

 

Appreciate your thoughts; Thanks!