I am also finding that the worksheet does not handle the sale of a home and the purchase of a new home correctly.  

When I use loan 1 for the old home that was paid off and loan 2 for the new home loan the average balance for loans is not calculated correctly.

When I run a separate worksheet for the home that was sold and another worksheet for the new home loan then add together the deductible interest agrees with how I read the IRS Pub 936. 

Loan 1. $29,671 interest 5/16/2017 orig. date $1,140,000 beg. balance

Loan 2/ $9,329 interest 9/9/2020 orig. date $1,732,000 beg. and ending balance (interest only loan)

ProSeries calculates $17,304 deduction.  I calculate the deduction to be $30,067