### 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)

save_mode = true;
}
void EditorPropertyPath::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_ENTER_TREE:
		case NOTIFICATION_THEME_CHANGED: {
			path_edit->set_icon(get_theme_icon(SNAME("Folder"), SNAME("EditorIcons")));
		} break;
	}
}
void EditorPropertyPath::_path_focus_exited() {
	_path_selected(path->get_text());
}
void EditorPropertyPath::_drop_data_fw(const Point2 &p_point, const Variant &p_data, Control *p_from) {
	const Dictionary drag_data = p_data;
	if (!drag_data.has("type")) {
		return;
	}
	if (String(drag_data["type"]) != "files") {
		return;
	}
	const Vector<String> filesPaths = drag_data["files"];
	if (filesPaths.size() == 0) {
		return;
	}
	emit_changed(get_edited_property(), filesPaths[0]);
	update_property();
}
bool EditorPropertyPath::_can_drop_data_fw(const Point2 &p_point, const Variant &p_data, Control *p_from) const {