Changed Category Permalink: Only the first post shows in Category RSS Feed

In WordPress Settings, Permalinks, Category Base was changed…

And when I install GN Publisher, the Category RSS Feeds only pull the first article from the respective category, when their are many articles for each category section.

I’ve tried /?feed=gn and /?category_name=new-name&feed=gn but the same thing happens… the RSS feed only pulls the first post from the category and nothing else.

The secondary issue is it’s pulling the entire first post and not respecting the Excerpt Only variable enabled within the WordPress, Settings, Reading section for external feeds.

Please advise how to solve this. I would prefer to use a different word for the Category permalink, but also want all articles to pull in the feed. Is this possible?

Thanks.