I'm a new Goggles user and have noticed that the Goggles are reporting the ISO setting incorrectly. The MP is set to 100 ISO and that is showing correctly on the app. However, on the goggles it is showing as 400!

Is this a fault or have I set up the system incorrectly?

May I know the firmware version of your Goggles? You may try to reset it in Settings to see if the problem persists.