"Compensation" requires "withholding" and all of that should be reported on the W-2.
How did you raise the cash for the withholding? Take if from your own pocket and hand it to your employer? Then it should be on the W-2. Did you sell some stock or was some stock withheld for taxes? That, too, should be on the W-2.
My response posited the entering of a 1099-B, not a W-2, where the WRONG BASIS was used; since brokers only report the "out of pocket: cost for this stock, ($0), and not the correct basis, this is often questions like this get asked.
If stock wasn't sold or withheld for taxes and you didn't hand the employer cash for them, how do you even know that taxes were withheld? Ask your payroll department to see if the taxes associated with the vesting are, in fact, on your W-2.
