MikeJones the option was preserved by Flarum at the REST API level.
However FriendsOfFlarum User Directory doesn't show that option for admins because it's a lot more complex to implement the logic for the UI.
I don't have the extension installed to try, but maybe if the sort option is specified in the URL it might still work? Otherwise we would be happy to receive a PR to make the sorting option dynamically available based on the user's permissions.
