Publisher center don’t index a particular category

Hello, I have a WordPress site where I publish articles, news, and more. The publisher center indexes most of my content, except for one particular category. Since it doesn’t provide any specific information about the issue, and I couldn’t identify it on my own, could you please help me understand what’s wrong with this category? 

Here’s the link to my feed which Publisher center somehow doesn’t index https://www.outdoorhaber.com/makale/feed/gn

Here’s another link which Publisher center indexes as soon as I publish a post https://www.outdoorhaber.com/haberler/feed/gn

What’s wrong with the first feed link?  Any suggestions will be appreciated.

Thanks in advance

ps: The first link doesn’t validate on https://validator.w3.org/feed/. It shows an error related to a very simple blog post, which is https://www.outdoorhaber.com/makale/buzul-nasil-olusur. This post consists of text and a few images. No scripts, nothing special to mention here…