Deductions & credits

Thank you.  I inputted the information and was stumped when asked to fillin the outstanding balance.  I put in "0" since it was paid off,  but not accepted.  I then tried $.01, no luck, then inputted the payoff of 37K and that worked.  Not sure if that was the correct number to use.   

 

What concerns me is after I inputted and check block 7 that the loan secured the home, I am now getting less of a refund.  Why is this the case?