Hey Paperbag,
Have you tried making the change while connected to your mobile connection and not connected to the Wi-Fi of the G34? What may be happening is that when you make the change while connected to the G34 Wi-Fi your phone/tablet briefly drops the connection before the setting is saved.
If that’s not the case, you should be able to log into the GUI (interface) to make these changes. Since your using the app you would go to “Access Web Interface” in the menu of the app, the username will be either the email address that you used to setup the app or admin and the app will give you the password, then tap the launch web GUI button. Once in the GUI you go to Connection > Wi-Fi > Networks. You should be able to make the changes from there.
Even when making the changes in the GUI, its a good idea to use a device that’s connected via ethernet or a device that is connected to a different network, it just helps to ensure that the connection doesn’t drop while trying to make the changes.
Hope that helps!
Hello Paperbag
In this case we would suggest you to perform restart on the modem for a minute when the app stuck on the loading screen and make sure that you stay next to the modem when you work on this steps. If still same issue persist you need to perform hard reset on the modem then re install app then after setting up you can try turn off the single SSID. But after resetting the modem will go to default setup any custom settings will be removed so use the default network name and password to connect to your network. If needed to perform hard reset in modem please follow the steps mentioned on link below
Let us know if this helps.