Deductions & credits

I did not refinance recently.  I had only one 1098 and that is what I said.  but when I went to the worksheet, it seemed to have two numbers, the one I entered as the current balance and a higher number, the origin of which I am not sure of.  I found a different article that said that 2 years ago (!!) there was a bug where it would take the original and the refinanced amount and sum them together and then declare you get little or no benefit.  I cleared the other number out, but the amount shown as the interest deduction only went up a tiny amount.  I finally overrode the actual entry, but I'm wondering why this should be necessary.