It has been a known issue for years, yes, but it is getting worse. Presumably an increase in HN users is making it hit whatever threshold triggers the closure flush much more quickly than it used to.
These days the links often expire for me within a couple of minutes (YMMV depending upon how close to 'prime time' you read Hacker News).
These days the links often expire for me within a couple of minutes (YMMV depending upon how close to 'prime time' you read Hacker News).