A 6% penalty is for an excess contribution. When entering your traditional IRA contribution, make sur that you answer No, when TurboTax asks of you recharacterized or "switched" your contribution to be a Roth IRA contribution instead. You did not. You converted to Roth (assuming that you have no Form 1099-R with code N or code R in box 7).
As baldietax said, TurboTax will also flag an excess contribution if you did not have sufficient compensation to support the traditional IRA contribution, but that seems unlikely under the circumstances.
