RSU Stock Sale 1099-B

This happens to me every year, but when I go to enter my 1099-B, turbo tax either double counts the income (already reported on my W-2) or assumes the entire thing is a gain. For example, I just uploaded a 1099-B for an immediate sale (upon vesting) of $24k of stock, and it adjusted my return down by about $13k. But these were shares sold SPECIFICALLY to pay taxes on the grant and had no loss or gain. Why does turbo tax think I need to pay $13k of taxes now?