Wordpress rss feed by category/tag in rss widget

I am trying to add a very specific Wordpress rss feed into an rss widget on our site, and am having trouble getting data.

If I pull the “main” rss feed http://{mysite}/?feed=rss2 I have no issues, but when I try to pull a specific category, ie [http://{mysite]/?cat=3183&feed=rss2](http://{mysite]/?cat=3183&feed=rss2) I get nothing.

Any thoughts on what might be the issue? Is it a conflict with a character in the URL? Is it an issue on the Wordpress side?

Any help would be appreciated.