### 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_disabled(p_read_only);
	clear->set_disabled(p_read_only);
};
String EditorPropertyNodePath::_get_meta_pointer_property() const {
	ERR_FAIL_COND_V(!pointer_mode, String());
	return SceneState::get_meta_pointer_property(get_edited_property());
}
Variant EditorPropertyNodePath::_get_cache_value(const StringName &p_prop, bool &r_valid) const {
	if (p_prop == get_edited_property()) {
		r_valid = true;
		return const_cast<EditorPropertyNodePath *>(this)->get_edited_object()->get(pointer_mode ? StringName(_get_meta_pointer_property()) : get_edited_property(), &r_valid);
	}
	return Variant();
}
StringName EditorPropertyNodePath::_get_revert_property() const {
	if (pointer_mode) {
		return _get_meta_pointer_property();
	} else {
		return get_edited_property();
	}
}
void EditorPropertyNodePath::_node_selected(const NodePath &p_path) {
	NodePath path = p_path;
	Node *base_node = nullptr;
	if (!use_path_from_scene_root) {