The speed test ran via XBOX or any Gaming Console is different to the actual speed test performed via http://www.speedtest.net.
Speed test result of Game Console is the measurement of your connection (at home) going to Game Console's Server. It is not the actual speed of your service.
While the speed test result from speed test websites is the connection of your home network coming from TPG's network.
In this particular issue, our Technical Team identified that there has been a line fault on NBN Network causing slow connection to the service and now being handled by our Engineering Team. Updates will be provided via SMS or Phone call when it becomes available.