Access to OS X Server from iOS 9

I am trying out the new Document Provider plugin in iOS9 for accessing shares on OS X Server 5.

I am finding a lot of inconsistencies between access from a Mac and access from iOS.

For example, I have two folders in a share point, with (as far as I can tell) exactly the same unix and ACL privileges.

I connect to the share point from a Mac and an iPad, using the same user credentials.

Both folders are accessible from Mac OS X clients, only one is accessible from iOS clients and I cannot tell the difference between them on the server.

When making batch changes to privileges on the contents of a share point, it is often the case that dismounting the share and remounting it again on Mac clients is the only reliable way to see the changes from the client's Finder.

It seems like iOS is very heavily caching privileges because I have never seen a change propagate to an iOS device. Even after deleting and re-creating the server's account setup in the "Mail, Contacts, Calendars" section of the Settings.app.

Does anyone have any suggestions?