Did the Form SSA-1099 that you entered on your tax return include federal income taxes withheld shown in box 6 of the Form? If so, did you enter those taxes withheld when completing the Social Security benefits received in the TurboTax program? If you did, those taxes would have been entered on your federal tax return Form 1040 on Line 25b. The total of all federal taxes withheld from all forms on your tax return is on Form 1040 Line 25d.
What exactly is the IRS questioning concerning the total of taxes withheld on Line 25d?