Currently I have a system where I draw fields representing the data of two ScriptableObjects. The problem occurs with the second ScriptableObject, which can not be bound to its SerializedObject until after the Editor has been created. It then has to be bound through a ChangeEvent in another field to update its appearance. I think the problem has to do with bindings to external SerializedObjects during the creation of the Visual Element Editor through the CreateInspectorGUI() function, as it works when done outside of it at a later point. Any help would be appreciated.
Ok, so I managed to find out the cause and the real problem. Everything I had in my custom Editor was actually working, but since I created it from another custom Editor and bound it to the SerializedObject after I had created the Editor, I basically reset all custom bindings. What ended up doing was first create an empty VisualElement, then bind it, then replace it with the CreateInspectorGUI().