A while back, I added 4K (2160p) episode images to Stranger Things - Season 2 from the 4K Netflix webrip that were far superior to the current 1080p ones (that are over-cropped with the brightness blown up). It took a really long time to get the perfect images, but I just noticed that they're all gone now. Is there any reason why for this? Usually I get a message or something if they were incorrect.

You can still see them in the cache at trakt.tv at the moment, but I don't have them on my at the moment. I preserved their native ratio as well (3840x1920 with black cropped bars added in), rather than overcropping to 16:9, so I'm not sure if this was the reason why. Just wondering why for future reference and if I should even bother doing 4K episode images in the future. Thanks.