ImageFap.com

Doesn't work for me either. Cannot remove images added to favorites gallery

In your case the thumbnail for Uncategorized is there because you have two galleries active in that folder. If the folder was empty I could fix it.

I've had the same issue. I click delete and it then shows un-delete (which is a great idea encase you made a mistake) although it never true deletes or removes the photo. Thereby throwing off the photo in relations to the album view. I get the delete to un-delete but it should completely delete once you save the album. Or remove from favorites if it is someones else's photo.