There appears to be some bug that is causing receipt validation to fail starting today.

This is causing features previously unlocked to become locked. This is not intended behaviour.

While I investigate the underlying reason, I believe you can restore access if you do either:

1. Force quit then relaunch Due, choosing to refresh for a receipt, or
2. Head to Due > Settings > Upgrade Pass > Subscribe > Restore Purchases.

Sorry for the inconvenience caused.