This is a really strange problem.
I have a category called "Work from Home Job" with permalink "work-from-home-job" that simply will not display with that permalink. I can change the permalink to anything else and it works fine. And the client really wants that permalink for SEO purposes.
The slug is not found anywhere else in the WP database. I verified this by deleting the category altogether and searching the database in phpmyadmin with no results.
The problem goes away when I disable the Custom Permalinks plugin.
I'm also running Yoast's SEO, but not sure if that has anything to do with it or not. I tried deactivating Yoast and the problem is still there.
Would really appreciate some insight here. Thanks!