Possible struct bug

I'm working on a timed event controller, here is the code (feel free to use it):

Code (CSharp):

1.  
2. //Libraries
3. using System.Collections.Generic;
4. using UnityEngine;
5.  
6. //Package that contains info about the event and how
7. //long it will last
8. public struct actionEvent {
9.     public System.Action action;
10.     public float timeLeft;
11.  
12.     public actionEvent (System.Action _action, float _totalTime) {
13.         this.action     = _action;
14.         this.timeLeft   = _totalTime;
15.     }
16.  
17.     public bool Run (float timepassed) {
18.         this.timeLeft -= timepassed;
19.         Debug.Log(timeLeft);
20.  
21.         if (timeLeft > 0) {
22.             action();
23.             return false;
24.         }
25.         else {
26.             return true;
27.         }
28.     }
29. }
30.  
31. //If an agent requires an event to occur during a certain time
32. //They will resort to this controller
33. public class eventController : Controller<eventController> {
34.  
35.     //List with all occuring events
36.     protected static List<actionEvent> events = new List<actionEvent>();
37.  
38.     public void Start() {
39.         //Start singleton service
40.         ActivateSingleton(this);
41.     }
42.  
43.     public static void subscribe (System.Action _action, float _totalTime, bool _overwrite = true) {
44.         actionEvent newAction = new actionEvent(_action, _totalTime);
45.         events.Add(newAction);
46.     }
47.  
48.     void FixedUpdate () {
49.         float delta = Time.smoothDeltaTime;
50.  
51.         for (int i = 0; i < events.Count; i++) {
52.             bool dumpEvent = events[i].Run(delta);
53.  
54.             if (dumpEvent) {
55.                 events.RemoveAt(i);
56.             }
57.         }
58.     }
59. }
60.  

The thing is, if I use actionEvent as a class, the time left counts correctly, going -0.02f everytime. But if I use actionEvent as struct, time left keeps stuck at the first decrement. This seems like a bug, could anyone explain me, why this happens?

 

Got what's going wrong, structs are always passed by value (never by reference), so when I do this:

Code (CSharp):

1. bool dumpEvent = events[i].Run(delta);

CSharp makes a copy of events and run it, it's not the same from the list I created, the workaround I found is this:

Code (CSharp):

1.  
2.             actionEvent e = events[i];
3.             bool dumpEvent = e.Run(delta);
4.             events[i] = e;
5.