I'm running into a reproducible problem in iOS 11(.0.1). If I take a marked up screenshot on one iOS device, then when the photo downloads onto another via iCloud Photo Library, the Photos app continues to show "downloading original" forever. The only way to get rid of that is to delete the screenshot and then kill and restart the photo app.
I think the problem is that I have iOS set to "Download and Keep Originals" photos and this seems to not work well with marked-up screenshots. Regular screenshots and photos work fine.
I think the problem is that I have iOS set to "Download and Keep Originals" photos and this seems to not work well with marked-up screenshots. Regular screenshots and photos work fine.