First, understand that there's no "income tax return reporting" requirement that means that you must use the RSU "guide me" interview. So one fix here would be to delete the trades you've entered and then use the default TurboTax 1099-B interview and enter the trades again, simply correcting the "$0" basis to the correct basis. To do that enter each trade exactly as it reads on the 1099-B then click on the "I'll enter additional info on my own" blue button. On the next page enter the correct basis in the "Corrected cost basis" box. The correct basis is (number of shares sold) x (per share "fair market value" used by the employer to calculate the compensation associated with the RSU vesting)
TurboTax will report the sale on Form 8949 "as reported by the broker" but will put an adjustment figure into column (g) of the Form, a code "B" into column (f) of the Form, and the correct amount of gain or loss which includes the adjustment.
If you really want to use the RSU "guide me" interview then the mistake you've made here is that you've told TurboTax about the same vesting twice and TurboTax doesn't "know" that. So it calculates exactly twice the amount of compensation as shown on your W-2. To fix that, break the vesting into two parts, one for the shares sold for taxes and one for your share. That way TurboTax has the correct number of shares to work with to calculate the compensation. Be sure to leave the "shares sold or withheld for taxes" box blank for both sales.
Tom Young
