there's something isn't right with Ni No Kuni wiki because yesterday I added a page for an enemy and added the categories https://ninokuni.fandom.com/wiki/Mouse_Sorceress then today I was looking at the wiki activity and the insights said there's a page without categories so I checked it and I got confused like is this some kind of a bug on the wiki? I added the categories but they still don't appear
You incorrectly added the </gallery> tag. Instead, you put the opening <gallery> tag on both where the opening tag goes and where the closing tag goes. This issue causes categories, and generally anything else below it to disappear. Don't worry, I've fixed it for you. The categories are supposed to show up now.