Property list not being able to save/publish

CMS 11.14.2

Ive implemented an IList<MenuItem> but it is not triggering the "Save/publish" button on change/add, what am I missing? 

Ive implemented the necessary items i think: 

[Display(Order = 340, GroupName = TabNames.Menu)]
[EditorDescriptor(EditorDescriptorType = typeof(CollectionEditorDescriptor<MenuItem>))]
public virtual IList<MenuItem> TopBannerMenu { get; set; }
[PropertyDefinitionTypePlugIn]
public class MenuItemListProperty : PropertyListBase<MenuItem>
{
}
public class PropertyListBase<T> : PropertyList<T>
{
        private readonly IObjectSerializer _objectSerializer;
        private Injected<ObjectSerializerFactory> _objectSerializerFactory;
        public PropertyListBase()
        {
            _objectSerializer = _objectSerializerFactory.Service.GetSerializer("application/json");
        }
        protected override T ParseItem(string value)
        {
            return _objectSerializer.Deserialize<T>(value);
        }
}

No javascript error in console, other property lists in solution are working.