I have been using Newsblur for several years now to keep up with international, national, and local news. After June of this year CBC news stopped updating. If I go to the website I can read the current news stories.
But if I use the Newsblur + and search for CBC BC, I do get a result to add. But I can’t read anything from that result past June. If I add the feed manually from the above web page, I can get current stories.
You found the right fix. CBC turned off the old http://rss.cbc.ca addresses at the end of June without redirecting them, so every subscription that still used one stopped updating while the https versions kept working. I’ve moved everyone who was still on an old address over to the working https feeds, so the CBC BC feed that search offers updates again now. NewsBlur will also try https on its own from here on whenever a site drops its old http address like this.