The deduction is not on the 1120S. it's only at the shareholder level that it's computed. the amount is transferred from the tax form to line\r 13 of page 1 of the 1040
In your 1040 look for form 8995. there are many factors that determine the QBI deduction besides the S_corp's net income. it can be affected by filing status, taxable income, whether the business is a Specified Service Trade or Business.
besides entering the 17V info make sure you complete the QBI section for the s-corp in Turbotax. turbotax dios not use that 17V info. (why?- don't know)
