iCloud not backing up third party apps
I have iCloud enabled and backing up on my ipad air 2 (recently upgraded to ios9) and my iphone 4s (ios8). I have documents and data enabled under icloud backup and I thought it was working fine since apple's apps are syncing.
I had one third party app that wasn't syncing between the devices so I thought it was just a bug in the app. Now I've downloaded another third party app and noticed it isn't syncing either and their support team is not aware of this being an issue.
If I go to iCloud - Storage - Manage Storage - ipad air 2, I see all my apps there with backup enabled, however all of them say No Data under them. I recently changed data in one of the third party apps so I know it needs to sync. Does this mean something's wrongwith syncing?
iPad Air, iOS 9