TurboTax is handling it correctly, as required by the IRS. You have to repay the Advance Premium Tax Credit that was paid to the insurance company on your behalf. The repayment is part of your tax liability. The fact that the amount of the credit was based on your income does not mean that it is an adjustment to your income. For more details see IRS Publication 974, Premium Tax Credit (PTC), which you can download from the first link below. You may also want to look at Form 8962 and it's instructions, at the other two links.
Publication 974, Premium Tax Credit (PTC)
Form 8962 Premium Tax Credit
Instructions for Form 8962, Premium Tax Credit (PTC)
