Xbox Live is currently experiencing some issues which are preventing some players from signing in. This is also affecting Xbox Live Cloud Gaming.
While the Microsoft team is are of the issues and working on them, we expect some downtime for some Xbox gamers. Thankfully this issue seems localized to a small portion of the Xbox Live playerbase.
For those effected that recently picked up an Xbox Series X, you're out of luck if you haven't downloaded your favorite titles. Worse, if you play games that rely on online connection to run (games like Destiny 2), you'll have to wait for maintenance to complete.
As this is a breaking story, we'll update with the latest news as it arrives.