### Godot version

4.0-rc6

### System information

Fedora 37, Mesa Intel ADL GT2

### Issue description

Code that works as expected at runtime fails with Nil references to (assigned) exported vars in the editor:

![tool_global_position_error](https://user-images.githubusercontent.com/364501/222031460-ffb1ecbd-5175-4a42-8470-25285ba5f821.png)


### Steps to reproduce

Try to access the `global_position` of a `Node3D` that's assigned to an exported var.

See that it works at runtime.

See that it errors in the editor with:

> Invalid get index 'global_position' (on base: 'Nil').

### Minimal reproduction project

[tool_test.zip](https://github.com/godotengine/godot/files/10856640/tool_test.zip)

s->call("set_instance_base_type", get_edited_object()->get_class());
	}
	
	Ref<ViewportTexture> vpt = p_resource;
	if (vpt.is_valid()) {
		r = Object::cast_to<Resource>(get_edited_object());
		if (r && r->get_path().is_resource_file()) {
			EditorNode::get_singleton()->show_warning(TTR("Can't create a ViewportTexture on resources saved as a file.\nResource needs to belong to a scene."));
			emit_changed(get_edited_property(), Ref<Resource>());
			update_property();
			return;
		}
		if (r && !r->is_local_to_scene()) {
			EditorNode::get_singleton()->show_warning(TTR("Can't create a ViewportTexture on this resource because it's not set as local to scene.\nPlease switch on the 'local to scene' property on it (and all resources containing it up to a node)."));
			emit_changed(get_edited_property(), Ref<Resource>());
			update_property();
			return;
		}
	}
	emit_changed(get_edited_property(), p_resource);
	update_property();
	if (is_script) {
		
		InspectorDock::get_singleton()->apply_script_properties(get_edited_object());
	}
	
	if (vpt.is_valid() && vpt->get_viewport_path_in_scene().is_empty()) {
		if (!scene_tree) {
			scene_tree = memnew(SceneTreeDialog);
			scene_tree->set_title(TTR("Pick a Viewport"));