Custom class does not show in inspector

 UNIVERSALINVENTORY:
 
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 [CreateAssetMenu(menuName = "Universal/UniversalInventory")]
 public class UniversalInventory : ScriptableObject
 {
     public List<UniversalSlot<UniversalObject>> Container;
 
 
 }
 
 [System.Serializable]
 public class UniversalSlot 
 { 
     public T KeyObject;
     public UniversalSlot(T keyObject)
     {
     KeyObject = keyObject;
     }
 }
 
 
 ITEMINVENTORY:
 
 
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 [CreateAssetMenu(menuName = "Item/ItemInventory")]
 public class ItemInventory: UniversalInventory
 {
     public new List<ItemSlot> Container;
 }
 [System.Serializable]
  public class ItemSlot : UniversalSlot
 { 
     public int CurrentValue;
     public ItemSlot(ItemObject keyObject, int currentValue) : base(keyObject)
     { 
     KeyObject =  keyObject;
     CurrentValue = currentValue;
     }
 }

ItemInventory will properly show the ItemSlot Container in the inspector, but not the UniversalInventory Container.. I'm confused as to why?