Don't know if this is the same problem but "Xbox One Signature Two" is not working for me and is showing a black background. I've checked the last few days and it hasn't fixed itself.
Still has a weird issue where on the preview on the site itself it still is black but when you view the link it will actually display properly. Not a massive problem but it can be a bit confusing at first.
Edit: Sometimes they show, and most of the time they decide not to.