Hello AVGVSTVS
Sorry to hear of the issues with content via the app and BT Sports, we appreciate the confusion this can cause and appreciate you taking the time to raise this via the forums.
As japitts has already advised, if the error message received is 'this is only available to view on your TV' this is due to it being a recording of Live TV and subject to restrictions applied by BT Sports themselves, is the recording still available to watch in your recordings via the set top box? As this shouldn't be effected.
Rob