When I enter my mortgage interest into the form (over $17,000) TurboTax is telling me that my deduction is $0, why is it doing that?

It keeps pushing me to the standard deduction, but if that $17,00 was used, my itemized would be close to $28,000, why is it not letting me take the deduction? This is for a first and only home, and the price is well under the $750,000 cap.