Why are the children of my Serialized Property not being drawn?

Hi all

I've been trying to use SerializedObject and SerializedProperty to draw some ScriptableObjects in the inspector:

 SerializedObject serializedKvp = new SerializedObject(kvp);
 SerializedProperty valuesListProperty = serializedKvp.FindProperty("m_Value");
 SerializedProperty modifierProperty = valuesListProperty.GetArrayElementAtIndex(index);
                 
 EditorGUILayout.PropertyField(modifierProperty, true);

What I'm getting is this:

Firstly, I don't want the "Element 0" label, which I presume is Unity trying to be "helpful" because my property is a List index.

Secondly, I'm telling the PropertyField to draw the children and I'm not getting any. If I double click the PropertyField I get this in a new inspector:

So you can clearly see that the property has child properties.

Can anyone explain to me why this is happening and how I can improve it?

Thanks, Ves