Having trouble selecting the slug you want in WordPress? If you’re like I was just a moment ago, you’ll try changing the slug on one of your categories to something different that you prefer, only to have WordPress change it back to whatever it was previously. What gives?
Turns out the solution might be simpler than you think — check your Post Tags for a tag with the same slug!
Slugs are shared between tags and categories, so if you use a particular slug with a tag, you cannot use the same one with a category, and vice versa.
Keep that in mind the next time you get all OCD about slugs!