acf_directory-settings is the key of a group saved as a PHP array.
In ACF Pro this doesn’t seem to work. If you load field group by ID saved in the database it works just fine.
The issue can be side-stepped by using the fields defined in the array with fields parameter, but since this is not available in ACF4 we need to do some checking to figure out the which arguments to use.
Let me know if there’s any way I can send pull requests to ACF Pro 🙂