Hi,
Same problem here as everyone: newly uploaded GIF are not animating. It seems that the image server is simply keeping the first frame and "discarding" all the other remaining frames when we upload it.
Here for example, this GIF of my latest game weight about 328kb. After uploading, it's now a 8kb GIF image with a single frame. So the issue seems related to how the GIF are processed when uploaded to itch.io.
Thanks for your hard work, I hope you'll be able to fix this, as is this very annoying to not be able to show players how the game "moves" in the description post.