UPDATE WORKS I've just tried again and it works. Reload the page and upload your screenshots to verify. @apple should advise all of us when they know there is an issue and when they are working on it...

Last year happened the same stuff: https://developer.apple.com/forums/thread/696455?page=2 Some users said that it could be a naming problem, others that it's an extension issue. Let me know if some of this works for you. I will also try. EDIT: I've tried to rename the images but didn't work, still an open issue.

Last year happened the same stuff: https://developer.apple.com/forums/thread/696455?page=2 Some users said that it could be a naming problem, others that it's an extension issue. Let me know if some of this works for you. I will also try.