Confirmation Emails Re-Using A Reference From The Past
If you have noticed a confirmation email referencing a reference number from the past, this is likely that you are looking at two different parts of the system.
Bookings
Bookings usually state Booking Reference before the reference number. These are which are usually sessions, admission ticket and experiences.
Sales Orders
Sales orders usually state Order Reference before the reference number. These are generally when a customer has bought something tangible, like a shop item, gift card (which can be for the recipient to booking an experience), adoption or membership.