Just if someone face the same issue, we implemented a workaround on our side.

We track all id of events. When we get an edit (eventEdited), we look for the id that is not present in calendar.events but present in the tracked list, this one is the original ID. Then we update the id in the list binded to the parameter [events] in a new copied array so this workaround can still work even if several edit are done on the same event.

//Every time we refresh the events (after update/add/initialization
// Events are stored in an attribute sourceEvents
private refreshBufferedEvents(): void {
    this.events = []; //The variable passed to mdb-calendar
    this.sourceEvents.forEach((event) => {
      const wEvent: MdbCalendarEvent = {
        id: event.id,
        startDate: event.startDate,
        endDate: event.endDate,
        eventStart: event.eventStart,
        eventEnd: event.eventEnd,
        longEvent: event.longEvent,
        allDay: event.allDay,
        oneDay: event.oneDay,
        summary: event.summary,
        description: event.description,
        color: {
          background: event.color.background,
          foreground: event.color.foreground,
        }
      }
      this.events.push(wEvent);
    });
    this.changeDetectorRef.detectChanges();
}



// To get the id of an edited event
const ids: Set<string> = new Set<string>();
this.sourceEvents.forEach((event) => {
  ids.add(event.id);
})
this.calendar_.events.forEach((event) => {
  ids.delete(event.id);
});
//Orginal id of edited event: ids[0]

Best regardsMichel