You are correct, Robin Hood is responsible for adjusting the cost basis of the replacement stock and the adjusted basis that's reported on your 1099-B when you have a disallowed wash sale. Because of this, TurboTax will calculate a loss for you to bear by default, since it doesn't have information about the replacement stock.
To manually adjust the cost basis of disallowed stock, enter the transaction exactly as it appears on the 1099-B. You'll see a bar at the bottom of the screen that says I'll enter additional info on my own. Then look for the option to correct the cost basis and make the adjustment.
@vicky12
