Global Custom Fields only visible for search by "root"?

I’ve got RT 4.0.18 running for our Service Dept. Somehow, I’ve prevented them from accessing Custom Fields when doing Searches. They can enter them into tickets and view them, but when they go to perform a Search none of the Fields are selectable/searchable. However, if I log in as “root” and do a Search, the fields are selectable. I know I’ve misconfigured something but I’m just not seeing it. Is there a permission that needs to be set for Global Custom Fields to show up in Search?