Function for separating Post & Media Categories = backwards result

I have added the recommended code to my functions.php file to separate Post Categories from Media Categories but the result is backwards.
i.e I have been adding categories to my media as I have uploaded each item. I then realized that all of those Media Categories were being used for Posts as well and showing up in my Blog Post Widgets. I added the recommended snippet but now all of the Media categories are missing in Media, but are still located in Post. Help?

Thanks!

Code added to functions.php file:

/**
* separate media categories from post categories
* use a custom category called ‘category_media’ for the categories in the media library
*/
add_filter( ‘wpmediacategory_taxonomy’, function(){ return ‘category_media’; } ); //requires PHP 5.3 or newer

https://www.ads-software.com/plugins/wp-media-library-categories/