Images in Image Occlusion can't be edited and new photos uploaded in notes only shows the icon

That is not possible. My best guess is that you edited different notes of the same image. When you create occlusions via add-on, each occlusion (i.e. square) is a different note. You are not creating sibling cards on one single note. In that sense, you may have been deleting files on specific notes which you won’t get back.