FindRelativeProperty never worked for me? how does it even work?

Using serialized properties/objects is very beneficial - but I always ran away from them in editor code cause I was never able to get a non-null/legit value out of FindRelativeProperty #-___-

Here's what I have:

FSMTrigger.cs

   public class FSMTrigger : BaseTrigger, Interaction
   {
     public List<FSMTriggerState> states = new List<FSMTriggerState>();
         // stuff...
   }

FSMTriggerState.cs

 public class FSMTriggerState : MonoBehaviour
 {
     public List<int> ints = new List<int>() { 1, 2, 3, 4, 5 }; // for testing
     public List<FSMTriggerTransition> transitions = new List<FSMTriggerTransition>();
     public FSMStateType stateType = FSMStateType.Other;
 }

FSMTriggerTransition.cs

   [ExecuteInEditMode]
   public class FSMTriggerTransition : MonoBehaviour
   {
     [HideInInspector] public List<EventDelegate> onTransition = new List<EventDelegate>();
     public FSMTriggerState toState;
     // stuff...
   }

For the sake of completeness:

 public abstract class BaseTrigger : MonoBehaviour
 {
    // stuff...
 }

 public interface Interaction
 {
     void Interact(UnityEngine.GameObject actor);
 }

Here's what I'm doing:

FSMTriggerEditor.cs

 void Test()
 {
         var spStates = serializedObject.FindProperty("states");
         for (int i = 0; i < spStates.arraySize; i++) {
             Debug.Log("STATE TYPE: " + spStates.GetAt(i).GetValue<FSMTriggerState>().name);  // <--- THIS WORKS
         }
 
         var ints = spStates.FindPropertyRelative("ints");
         for (int i = 0; i < ints.arraySize; i++) {
             Debug.Log("Numbers: " + ints.GetAt(i).GetValue<int>()); // THIS DOESN'T
         }
 
         var spTransitions = spStates.FindPropertyRelative("transitions");
         for (int i = 0; i < spTransitions.arraySize; i++) {
             Debug.Log("Transitions: " + ints.GetAt(i).GetValue<FSMTriggerTransition>().name); // NOR THIS
         }
 
 }

I wanted to make sure that the problem is NOT with the state class itself, so I went ahead and:

FSMTriggerStateEditor.cs

 private void test()
 {
     var spTransitions = serializedObject.FindProperty("transitions");
     for (int i = 0; i < spTransitions.arraySize; i++) {
         Debug.Log("Transitions names: " + spTransitions.GetAt(i).GetValue<FSMTriggerTransition>().name); // THIS WORKED! SO AS THE INTS OF COURSE
     }
 }

So it's pretty obvious that FindRelativeProperty isn't working right - maybe I just don't know how to use it - but I've seen a lot of scripts just reference the thing like I did - there's no special path - just the name of the variable I want to fetch. Yet it's not working with me - I get null reference exceptions. Even if I try the simplest of examples :(

Any help would be greatly appreciated - thank you very much in advance.

EDIT: There was a mistake in the test script using FindRelativeProperty - although I fixed that, it's still giving me a null ref:

     var spStates = serializedObject.FindProperty("states");
     for (int i = 0; i < spStates.arraySize; i++) {
         var state = spStates.GetAt(i);
         Debug.Log("STATE TYPE: " + state.GetValue<FSMTriggerState>().name); // WORKS

         var ints = state.FindPropertyRelative("ints");
         for (int j = 0; j < ints.arraySize; j++) { // BREAKS HERE - MEANING INTS IS NULL
             Debug.Log("Numbers: " + ints.GetAt(j).GetValue<int>());
         }
     }

EDIT:

Forums crosslink.