When the advanced setting "mark as read after x seconds" is enabled and the article filter is set to show only unread or new articles then selecting one of the unread/new article will cause it to be automatically marked as read after x seconds. Then the selected article that is no longer considered unread/new is filtered out of the list and the next unread/new article is selected. After x seconds, again, this newly selected article is automatically marked as read and the process repeats, until there are no more unread/new articles and the initial list unread/new articles is now all marked as read. The behaviour is not useful and prevents the setting "mark as read after x seconds" and the unread/new filter from being used at the same time. Don't know in what version this behaviour started, but older versions allowed these two features to be used together in a useful way. I could filter the unread articles and when I looked at an article it would be, after x seconds of looking, automatically marked as read but the list would only change if it was refreshed (F5) or the filter changed. VERSIONS: KDE 5.29.0 Qt 5.6.2
*** This bug has been marked as a duplicate of bug 350731 ***