Thanks for a quick response, My personal at one point was GIPHY, or VN video editor, i make a video then i convert it into a GIF, also check if your basic / background layer isn't transparent, to optimize the "GIF" a lot of apps just put in these lines because they think it's blank space, also you might want to check if you don't have automatic dithering option on, and the last one, maybe first try to resize your canva by puting it into pixaki intro / pixaki pro and then apply it to all layers, maybe the programm is just cofused by the size of your art and automatically tries to fill in the blanks. I hope one of these solutions help :p , let me know how it went, and I hope you're gonna keep creating such nice content!