Mortgage Interest Deduction not calculating?

Hi - I'm entering our mortgage interest into TurboTax and it doesn't seem to be calculating the full deduction. Our loan is <$750K and secured by our primary residence, no points. While the loan is a refinance of previous loan, the loan is the most recent and was not used for anything except paying off existing loan. Overall, very simple and straightforward mortgage. The mortgage interest entered is $19,500 and resulted in a tax reduction of approx. $400 (2% of MI amt). In previous years using TT for the same loan, we've seen a pretty big reduction (usually thousands of dollars) in taxes owed after entering mortgage interest, so this is unusual. Also, I entered a charitable contribution ($1720) after entering the mortgage interest and our taxes owed went down by $415 (24% of donation amount). 

 

I looked at Schedule A and Form 1040 and both seem to be capturing the full amount of mortgage interest entered. I scoured the internet and don't see anything about tax laws changing related to the mortgage interest deduction.

 

I'm totally puzzled and would love any thoughts or ideas of what may be happening and how to fix it. We want to ensure we're getting our full tax benefit on this deduction. 

 

Thank you!