I was adding the pages for Burrower Circulator/Primary Nerve etc. And I went back to the Burrower Page and noticed the categories had been repeated, so it said: Categories, Mu Override, Machines, Mu Override, Machines, you get the idea. I can't remove these extra categories so I just wanted to point them out to anyone who can.
Edit: On closer inspection, I realised this also applied to other machine pages, including Watcher.