I see a problem now.
I created backup copy of your site files and data (except wp-uploads) and installed its copy at my local development environment. When I login as a humanresources user and open the 1st post from the list for editing, I see the list of allowed categories.
But the same meta box shows empty categories list at the production site. I assume that some database error may take place at your installation. Can you look at the system logs for the PHP or MySQL error messages from your server? May be temporal setting of WP_DEBUG and WP_DEBUG_LOG to true may help to see the error message.
