Adding EventTrigger.Entry to EventTrigger component via script doesn't update component's editor UI

When adding an entry to EventTrigger via script, the delegate is not displayed in the Event Trigger's editor UI as one would expect. If you change to "Debug" mode in the inspector window, you can see that there is a second delegates array that does contain the functioning entry, however. Is there a way to approach this that will display the UI components correctly or is this just a bug / intended?

 void Start()
 {
     EventTrigger trigger = AddComponent<EventTrigger>();
     EventTrigger.Entry entry = new EventTrigger.Entry();
     entry.eventID = EventTriggerType.PointerDown;
     entry.callback.AddListener((data) => { OnPointerDownDelegate((PointerEventData)data); });
     trigger.triggers.Add(entry);
 }
 
 public void OnPointerDownDelegate(PointerEventData data)
 {
     Debug.Log("OnPointerDownDelegate called.");
 }

Debug:

Normal: