Possible Issue with Secure Section 603 Roth After Tax?

An employee is only deferring before tax to the 403b.  Since her deferral is a flat 15,000, it exceeds the 80% maximum limit.  The deductions are correct, the limits are correct, but when you look at the review paycheck screens there is a listing for AFTER TAX (Roth).  It doesn’t take anything deductions in error.  Why does the review paycheck screen show this row if the employee didn’t elect Roth and shouldn’t have any excess go to the Roth due to section 603?  When we bonus her so she doesn’t exceed the 80%, this line goes away.