You just connected your InvizBox Go to a Wi-Fi hotspot. Once the Administration Interface reloaded you were logged out and had to log back in.
InvizBox Go token timeout
When you initially connect to your InvizBox Go's Administration Interface your browser will be issued with a timestamped token. This token will allow you to use the Administration Interface without having to log in for a period of time.
When you connect your InvizBox Go to a Wi-Fi hotspot your InvizBox Go will update its system time to the current time. This creates a disparity between the time on the token your InvizBox Go issued to your device and the InvizBox Go's system time. This in turn will make the token invalid as the time will have "jumped" forward and you will need to log in once more.
What can you do?
We suggest that you select "Remember Me" on the log in page of the Administration Interface. Or use the InvizBox Administration application that is available for Android and iOS. Both of these methods will prevent you from being logged out if there is a time "jump".