TP refinanced existing home acquisition debt of 963K.  Married.  This old debt was qualifying home acquisition debt and it existed prior to 12/15/2017.

The new debt was 19K more than the old debt.  This is home equity debt.

Home equity debt interest is not deductible, as it was not used to buy, build or substantially improve the home

How is the non-deductible interest calculated when there are several home offices for different businesses?  The diagnostic says use the input at the bottom of Screen 25.