I just got feedback from the support team:

Thank you for waiting! I sincerely apologize for the inconvenience. This issue has been reported and our Engineers are currently looking into it. As of the moment, there is an investigation created regarding FNB Bank Error and hopefully, this will be resolved as soon as possible. As of writing, we don't have any turnaround time on when it will be resolved. We also understand that you, as one of our customers, rely on our service for your business. As such, once the issue is resolved, I will send you an email straight away so that you will be notified as well.