Cannot add new article

Based on the screenshots it seems like you already have sections added but not reflecting while adding a new article.

Still, just in case just check whether the sections work? Here’s a knowledge base article on this https://codesavory.com/basepress/knowledge-base/adding-content/adding-sections/

Also just to be sure, if you have any other plugins active on your site, temporarily disable them just to make sure this is not happening because of some conflict.