Why is the taxable amount in my 1099r 2a not reflected in my 1040 4b?

I did in-plan conversions from after-tax 401K to Roth in 2018. My 1099r from Vanguard shows $55.95 in both "2a Taxable amount" and "14 State distribution." The distribution code is G. However, in the 1040 TurboTax created for me, box 4b "Taxable amount" is 0. Should it be $55.95 as in my 1099r? Did I miss something? Thank you for your help.