ALF for Mobile - When clicking Submit on iPhone mobile app the upload fails

Question
We have a customer who is not able to use validation on the iOS mobile app .They get an 'unauthorized 401' error (see attachment), however if they fill out a form and do not mark a validation field the data uploads ok because it doesn't 'stop' on the iOS mobile app for validation.

Answer
If the server doesn't have a valid SSL certificate, the iOS devices will "time out" the self-signed certificate after 15 minutes of inactivity. You can get around this by logging out of the app and back in again but you'd need to do this every 15 minutes.
All communication for the clients is done over HTTPS (port 443) and all communications should have the Authorization header sent by the client.
If there is a valid SSL certificate, the last suggestion is that the proxy isn't passing credentials every time it should to the actual ALF server.