Previous Balance Invoice Numbers

SUGGESTED

When I print a bill with only a previous balance Timeslips does not use the original invoice # from which the charges originate, but instead generates a new invoice number. This is confusing for some of our clients, thinking there is a new invoice/balance due.  I've read previous posts regarding this and the "fix" and to make sure Timeslips has the setting of "show invoice number on: bills with new charges.  This is our current setting, but it still generates a new invoice number for previous balances only.  Is there something I'm missing?  I'm using TS Premium 2020.