Sounds like you had tax due last year on a 2018 return. Maybe you paid it. TurboTax never knows if you paid the tax you owed. The online account will only show the results of the tax return you prepared and does not update when or if you paid the tax. That information is not shared with TurboTax by the IRS or state.
No, it was not added to your 2019 tax bill. Each tax year is separate. If you really still owe it, you will hear about it from the IRS or state someday. Meanwhile, check your bank/credit records to see you paid it last year.