Bookings Bug: Attendees Rescheduling AFTER Appointment Time

Previously to last month, attendees that scheduled with Bookings were not able to reschedule after the appointment has ended. Now, we are experiencing issues where the attendees are rescheduling after they missed an appointment - and this is an issue because Bookings recycles the self-service appointment ID (which we use in an Automate rule to circulate the appointment details for notes by the staff member, which are round robin picked). Was this always a feature or was there a change in the Bookings code?