Can I assume your a NOW broadband customer and the tag you have referred to is actually the router?
The NOW box is a streaming device for the app and other third party apps like iPlayer and ITV hub.
Have you tried doing a factory reset to the router by holding the reset button for 15 seconds?
Worth try unplugging the router if you haven’t done so but for 3-5 minutes.
Worst case give the team a call and they should be able to sort it for you.