Story Unavailable - Apple News App

When I attempt to open a story in Apple News from the Safari sharing button, I frequently get the message: 'Story Unavailable - This story is not available in News'

I used to be able to add RSS and other web sites to my 'favorites' section but now it does not seem to work anymore.. Is there a way to manually add RSS or news articles to Apple News in iOS 10.x?

Thank you