I have the same scenario. I went into the transaction pulled from my broker, and adjusted the cost basis to equal proceeds (W2 income plus cost basis), which leaves a zero gain. The total gain is already reported on my W2. TT is now telling me this line needs review. Not sure if this makes a difference, but on the broker 1099-B under the section labeled Short term transactions for covered tax lots, it says the basis is provided to the IRS on line 12.
