Did you already perform the power cycling steps I mentioned previously? If so, let's see if alternate DNS servers will help. From the Xbox One home screen, go to Settings > Network > Advanced settings > DNS settings > Manual. (If Settings doesn't appear on the home screen, select My Games & Apps, then Settings). From there, enter the Primary DNS as "208.67.222.222" and the Secondary DNS as "208.67.220.220". If that doesn't help, try using the google DNS servers which are: primary alt number 8.8.8.8 - secondary alt number 8.8.4.4. Let me know what happens.