When a privacy rule on "find this in searches" is turned on for a data type (meaning users don't have permission to find the data type in searches), the data type's associated slugs will not work.

To work around this, you can have "find this in searches" checked for the data type that you want to use slugs for. If you opt to use this workaround however, please note that this will expose the data type.

Our product team is considering how we can enable more granular privacy controls over slugs in the future.