RSS does not work if you do not go to the site

I noticed the strange behavior of the habralents (normal, not 3.0, from the url of the form habrahabr.ru/rss/lenta/HEX_HERE ): if you do not enter the site, then the RSS is not updated. I use the built-in reader Opera 9.64 / Linux. Even if the pens press Update - it still does not update. And if you go to the site - after a while (or immediately, if you click Update again) the RSS is updated and new topics arrive.