Subscriptions bought with your Apple account sometimes need to be restored or reconnected with your Jottacloud subscription. This can be done from the Jottacloud app Settings.
Tap "Buy subscription"
Tap "Restore subscription".
If you have a valid purchase on your device, this will be connected with your Jottacloud user. If you have any issues, please contact us at firstname.lastname@example.org and we will help you further.