Do you know the difference between expense and expenditure? Example:

If there is debt, the principle is the expenditure which reduces the running liability balance. Interest and any fees are an expense. I've seen people enter the entire payment as expense, and later try to adjust the loan balance when they get a 1098.

Also, an S Corp has payroll. We don't know how that is being managed, but that's a common place to find this type of error.

Lastly, you might try thinking of this differently: "After entering Taxpayer income and expenses for his S-Corp"

You are entering the S Corp's income and expense, as an operating entity independent from Humans who are the shareholders. Your tax filing is the S Corp. They are not "his" income or expenses.