So I have my mobile and broadband Cable with Optus but even when I’m home I get a message stating I have gone over my data usage for the month and am about to be charged another $10 for more data but technically it should be using the wifi also the speed in my house is stupid slow and constantly pauses. Even just trying to post this I’m getting errors. Also my broadband information is not connected in my on phone app.
You need to turn mobile data off otherwise there is no guarantee your mobile will use your home WiFi connection. Have you raised your concern with Optus about your home internet being slow? If you restart your cable modem that may be a quick fix.