Custom Post Type Categories Not Working at all

Here in my default theme website https://webguidesolutions.com/blog/. On the right side you can notice two categories i.e. Cat and Wild animals. When I click on ‘Cat’, I may able to see one post by name ‘meow’. But the case is not same with Wild animals. I have posted one post in ‘Posts’ to which I gave category as ‘cat’ and one post in ‘Custom post type section’
to which Igave category as ‘Wild Animal’.