Withdrawals of excess HSA contributions are subject to income tax but not the penalty.
If you made HSA contributions through your employer, those contributions are pre-tax. They're not included in your wages on your W-2. Therefore, any excess contributions that are withdrawn have to be added back to income since they were incorrectly deducted. TurboTax is correctly adding the withdrawal to income.
However, because you did withdraw the excess contributions, you're not subject to the excess contribution penalty or the HSA penalty.