### 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)

assign->set_icon(Ref<Texture2D>());
		assign->set_text(p);
		return;
	}
	Node *target_node = base_node->get_node(p);
	ERR_FAIL_COND(!target_node);
	if (String(target_node->get_name()).contains("@")) {
		assign->set_icon(Ref<Texture2D>());
		assign->set_text(p);
		return;
	}
	assign->set_text(target_node->get_name());
	assign->set_icon(EditorNode::get_singleton()->get_object_icon(target_node, "Node"));
}
void EditorPropertyNodePath::setup(const NodePath &p_base_hint, Vector<StringName> p_valid_types, bool p_use_path_from_scene_root, bool p_pointer_mode) {
	pointer_mode = p_pointer_mode;
	base_hint = p_base_hint;
	valid_types = p_valid_types;
	use_path_from_scene_root = p_use_path_from_scene_root;
}
void EditorPropertyNodePath::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_ENTER_TREE:
		case NOTIFICATION_THEME_CHANGED: {
			Ref<Texture2D> t = get_theme_icon(SNAME("Clear"), SNAME("EditorIcons"));
			clear->set_icon(t);
		} break;
	}
}
void EditorPropertyNodePath::_bind_methods() {