Serializing list of base and derived classes with custom inspector

Hi everyone!

I have a problem trying to save an array of a list of custom base and derived classes. I have tried to follow the Serialization Megapost but I am still unable to save the data within the array of lists.

GameConfigManager:

 public class GameConfigManager : MonoBehaviour
 {
     public MultidimensionalCategoryGame[] categoryGameList;
     public int playsToUnlock;
 }

---

MultidimensionalCategoryGame.cs

 [System.Serializable]
 public class MultidimensionalCategoryGame : ScriptableObject
 {
     [SerializeField]
     public List<Powerup> array;
     
     public void OnEnable()
     {
         hideFlags = HideFlags.HideAndDontSave;
         if (array == null)
         {
             array = new List<Powerup>();
         }
     }
 }

---

CategoryGame.cs

 [System.Serializable]
 public class CategoryGame : Powerup
 {
     public int discount;
     public string[] instructions;
     
     public override void OnEnable()
     {
         base.OnEnable();
         
         if (instructions == null)
         {
             discount = 0;
             instructions = new string[0];
         }
     }
 }

---

Powerup.cs

 [System.Serializable]
 public class Powerup : ScriptableObject
 {
     public string name;
     public string description;
     public float cost;
     
     public virtual void OnEnable()
     {
         hideFlags = HideFlags.HideAndDontSave;
         
         if (name == null)
         {
             name = "";
             description = "";
             cost = 0;
         }
     }

From my testing, I can save the integer playsToUnlock variable within GameConfigManager. I can also enter data for the MultidimensionalCategoryGame objects in the inspector, but when I hit play my data within MultidimensionalCategoryGame objects are not saved.

Sorry for the long post! Thanks for your time and please help!!!