Old threads with no new posts in them showing up in my "Recent Forum Posts"

This has been happening for a couple weeks now. When I click on Forums -> Recent Forum Posts, partway down I see threads I've read previously and when I click on them and scroll to the bottom expecting new posts in the thread, there are none. Doesn't matter if I close my browser, refresh the page, etc., there are always quite a few in there and they're generally older ones too, not something I read yesterday, could be a week ago.