If you are correct (and you're probably not*), the problem is with the VT Dept. of Taxes, not TurboTax. Form IN-111 and the instructions for line 1 say you start with "Federal Adjusted Gross Income (federal Form 1040, Line 11). "
* "(21) “Taxable income” means, in the case of an individual, federal adjusted gross income determined without regard to 26 U.S.C. § 168(k) and............."
https://legislature.vermont.gov/statutes/section/32/151/05811
