I recently updated one of my WordPress Sites and noticed that my site’s News menu didn’t display any articles. I poked around at my site’s posts and didn’t notice anything wrong with them, they were all set with the right category.
A quick Google search delivered the answer for me, but it was buried in a forum post. During one of my updates, I must have somehow corrupted my site’s Permalinks settings. I changed the Permalinks setting, then set it back to the original setting and my News category menu now works.