Bill Subtotal by Reference Doesn't Show Total Amount on all bills

SOLVED

I recently upgraded from Timslips 2010 to 2019.   I use a standard template for all bills which have clients with more than one reference.  On most of these, at the end of each reference, it shows the total number of hours and the total amount charged for the referenced matter.  However, on some bills (even though the same template is assigned) it shows the total number of hours, but for amount charged, it shows $0.00.

At the end of the bill,  it prints the total number of hours and total amounts charged for all reference items.  I tried re-assigning the template to the client in question, but it doesn't change things.  I can't understand why two clients with the same template show different results.  Any help please?