Flash Briefing Caching Content

We noticed recently that the number of downloads for content in some of our client's flash briefing skills has gone down tremendously. This is not the number of downloads for the feed itself, which I realize is cached and updated every 15 minutes on Amazon's side. This is the actual number of downloads for an episode in the feed. I would not think that this content is cached, however, when making requests via my Echo for one of the Flash Briefing skills, I do not see any requests come through for the content server side. If I access the content in the browser, the request comes through automatically.

Is the content of a Flash Briefing feed cached on Amazon's side? This would be the content that lives in the <enclosure url> tag for RSS feeds and in the "streamURL" field for JSON feeds.

In our server side logs, we used to see a large number of downloads from the user agent "AlexaMediaPlayer." However, now we do not see any downloads from that user agent, and only a couple each day from the user agent "AmazonNewsContentService."

Does anyone know the difference between these two user agents? And why we would suddenly stop receiving requests from the "AlexaMediaPlayer" agent?

Thanks in advance.