We apologize for the delay in communication, we have been doing everything we can to fix this Xbox connection issue.
Two things went wrong. Something happened with our security certificates from Microsoft which made it so none of the Xbox players could connect. When putting in the new certificates they are not being recognized by our servers so we have been working with Microsoft all day to figure it out. Eta for fix is hopefully in a few hours, but more realistic due to the issues we have had all day is tomorrow morning.