Shift+F5 to reload everything fully, clearing all cached data relating to the site. Computers do this thing where they don't re-download everything every time you load a page, but keep a sort of saved copy of the data for quick reference. I for example see this:
avatars take forever to update, even with reloading browser cache. They also get cached on the website somewhere. I haven't changed my avatar since they were added in game, but I heard it can take up to an hour or two sometimes. Just be patient always :P, seems it updated already anyway.