Hi there, @kirstiehope.
I see you reset your console, modem and router, but did you hard restart your console as well as unplug your network equipment for 2 minutes. If not, follow these steps: unplug your modem, router and console. After 2 minutes plug in the modem and router. Let them come back online completely. Then plug in your console and start it up. Let me know if that helps or not. Thanks!
Just to confirm, your Xbox is wired and not on wireless, right? Also, try using alternate DNS servers. 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.
Great! You're very welcome. If you have any other issues, please reach out to us again. Good luck and have fun 
Hello, @jasterdad.
Those suggested DNS settings are not game specific. If you can't connect, the first thing to try is power cycling your equipment with the following steps: unplug your modem, router and console. After 2 minutes plug in the modem and router. Let them come back online completely. Then plug in your console and start it up. Let me know if that helps or not. Thanks!
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