Thank you for the detailed accounting of the issue. I could not see the update on May 13th. It's been more than one day since I last tried though and the update still does not show up. This definitely seems like a feedly issue, since a day has passed and the update does still not show up.
Granted, according to feedly, only one other person has subscribed to this feed. Still according to them, one day would be the maximum to re-fetch information from the site. Not sure if some https caching here is at play.
There's an RSS link in that page but when I added it to the RSS aggregator service I'm using - feedly - the latest version/thread presented was about version 220.127.116.11. Can you look it up? I'm using a bunch of feeds to be notified about software and especially security-related updates, and something seems screwed up here.