Summary:
Always log in to the app by scanning your QRCode. Don't clear your cache unless instructed to (and log in with QRCode straight afterwards)
Detail:
Because not all customers have WiFi (or they may not be happy for you to use it) and a good mobile data signal cannot be guaranteed in much of the UK, the system is designed to work offline using cached (stored) data, and to cache updates that are being sent to the office until a connection is available. The cache "knows" who it "belongs to", and that information can be used even to allow offline log ins, with the following limitations:
- You must log in using QRCode scan
- You must have previously logged in by scanning your QRCode and not have subsequently cleared your cache.
You cannot log in using user name and password with no signal, as the phone cannot authenticate without communicating with the server.
If you have a very weak signal, there may be problems trying to communicate with the back end that mean you are better off putting your phone into air-plane mode to force an offline log in (though obviously this will mean that you will be using stale - in other words old and potentially out of date - data).
If you are offline and check in to a booking (you will see a red header banner in this case) you should consider (if you have any kind of signal) sending an SMS message to your coordinator or equivalent so they know it is OK to snooze the alert they will get.