The recent activity module seems to only update when the page that it's on gets edited, or if you manually add ?action=purge to the end of the url. This page should be used to check recent activity, as it's always up to date and shows more comprehensively what's going on.
I was only briefly active at the end of last year and I didn't visit much since December and I'm really surprised, the Wiki looks really nice and doesn't feel abandonded anymore. It's a very welcome change and hast boosted the quality for sure, thanks for taking the initiative (taking over administration and all that) and doing all that work. And of course thanks to all the other contributors and new admins!