>>86082411Each frame is stored as an image with the size of the smallest bounding box of all pixels in that one frame. The background is transparent. Each frame is then offset to centre it. And having a frame size different from the image size breaks the thumbnail generator I guess. Having each frame be the same size as the image with the rest filled in with transparency works fixes it. You can use "magick a.gif -coalesce b.gif" or photoshop or something.
