posts showing in all categories

So I made a custom menu and different categories to be able to organize my posts. However I just realized that regardless of what category I click on I end up seeing all my posts. Does anyone know why that is? What do I need to do, in order to be able to only show the posts that correspond with that category.

Here is an example https://walkinginthedesert.com/category/book-reviews/

only one of those is a book review.