Youtube playlist RSS feed not updating

At the start of the year, I purchased the season of Adam Ruins Everything. I found the link to the RSS feed: . At first, it worked fine, but although the feed now shows new videos, Newsblur has not added anything since January 9. I even tried clicking the insta-fetch stories button, but it doesn’t work.

I’m having the same issue with a different playlist (

The RSS feed looks like it’s updated properly (I don’t know the format so I’m not certain, but it has entries for the latest videos), but newsblur doesn’t show anything newer than december 9th.