Graalians - Is uploading to classic glitchy?

I have a file I keep trying to upload. It is a gif. Whenever I look at the file, it looks fine and has no full black/full white issues. When I made the background all the same color red and click "set transparency" it doesn't change it. The entire background remains red. When I make the entire background transparent, it looks fine in any viewer (even the Graal depot customs viewer) but when I upload it to Graal it shows a preview of a seriously messed up looking image, turning some of my colors green and overlapping some of my animated effects. Also gives the background a big square flashing different colors that never even existed. Any ideas? Thanks