How do I serialize my array in my base using Custom Editor?

Hello,

I've built a custom editor script but I can't save the data upon play. Also note that I do not need to have the data visible in the Inspector, just that it needs to be there upon playing.

 [System.Serializable]
 class InterfaceTest: MonoBehaviour {

   [SerializeField]
   public IMyInterface[] interfaceArray = new IMyInterface[0];
 
   void Start(){
 
      Debug.log(  interfaceArray.Length ); //produces a 0, which is bad
 
   }
 
 }
 
 
 using System.LINQ;
 using UnityEditor;
 
 [CustomEditor(typeof(InterfaceTest))]
 class InterfaceTestEditor: Editor {
 
   public override void OnInspectorGUI (){
 
     serializedObject.Update();
 
      InterfaceTest myTarget = target as InterfaceTest;
 
      myTarget.interfaceArray = myTarget.gameObject.GetInterfaces<IMyInterface>().Cast<IMyInterface>().ToArray(); //my ext method stuff + LINQ
 
      Debug.log( myTarget.interfaceArray.Length ); //produces a 1, which is good
 
      serializedObject.ApplyModifiedProperties();
 
   }
 
 }

I need to always be able to refresh the InterfaceArray in case I add or remove scripts that implement . In OnInspectorGUI, I receive a value showing that it finds a script and should work...but upon playing the game I don't have that value stored in myTarget/base script which I need it to have. Any help on this would be greatly appreciated, thank you!