Mod Thumbnail not Changing after setting Primary Image

[CobaltZxHans]

EDIT: The image updated in its own. I guess it resolved itself lol.

I recently created a mod for Ace Combat 7, and I added a new image I wanted to use for the thumbnail.

However, I set the new image to be the Primary picture, and almost 24 hours later, it still hasn't updated.

What am I doing wrong?