Please check out our Device Guide to ensure it has set up and connected to the right network mode.
Please also check that there are no reported network issues at your location.
Let us know how you go.
I'm not sure why you are trying to access that link? Is it mentioned in the Device Guide?
I can't seem to find that instruction, I've also provided some feedback to the team that looks after the Device Guides page as the images of the modem settings are difficult to see.
You're right, there is a possibility that it is faulty. You can Chat with us to do some more troubleshooting with the Technical Support team and arrange for a replacement device if needed.