Earlier this week, Xbox One users started experiencing an issue with their sign-in that basically prevented people from logging in. Today, it appears to have been fixed. The original problem was making it so people couldn't get in, and when you could, there was an issue with redeeming digital codes or retaining previous digital purchases. In a social media post this afternoon, the official support channel confirmed they've worked out the issue.
The earlier issues with accessing previously purchased content & purchasing new content should now be resolved. Thank you for reporting this issue to us, we're here and listening. https://t.co/njjyDCGfYA
— Xbox Support (@XboxSupport) February 1, 2019
As we're writing this, however, there still seem to be some people experiencing issues with their games. We'll keep an eye on it and see how this develops, but it seems like the company may need to do some individual damage control for some users if its been fixed across the board but still have pockets of Xbox One owners with lingering issues.