A little bit more info...this happened to one of my users yesterday and the message wouldn't go away. All last week he was using Fields Maps with no issues. At the end of his work day he plugs his IPad in to a charger and places his device in a cabinet. This is what he did on Friday. He is not powering down the device or signing out of anything. The below image is what appears. Tapping Later makes the message reappear. Tapping Sign In asks the user to sign back and when he enters his credentials, it just brings the authentication error message back. I attempted to login in as myself and had the same thing happen. If I login to my own IPad, I don't encounter this error. However, I am not out in the field actively using Field Maps so that may not be a good test. I also did this using wifi and cellular and didn't receive the authentication error.
Our current work around is to sign out of Field Maps and sign back in. I am waiting to hear back from my end user as to whether this provides a permanent solution or if he periodically receives the authentication error, needs to sign back in and how often this occurs.
