Hello

This is, as far as I know, an always existing (mis)-behaviour.

No, I have a version 2.3 live here: http://www.jernbanen.dk/forum/
where it works as expected. Tested in Chrome and Edge.

It only seems to work, because when I open the thread in the whole-thread-view, the forum marks all messages of the thread as viewed. But this assumption is wrong. As an example I opened the thread "exit mugabe" in your forum and read only the first two messages. Anyhow, all (actually) eight messages are marked as read. And, not to forget, this marks are set with a cookie, except I am logged in and the list is hard limited to 200 postings.

With the version 2.4 we replaced the old cookie or user-settings based read-marking with a new approach, that is browser based for non-registered users and database-based but independent from the user-settings for registered users. At that point we removed the set-all-read-behaviour. It's comprehensible to get a correct listing of the read postings from the visitors view. Actually neither the new nor the old behaviour comply the task.

We'll discuss this in public here and internally in the Github-issue #288.

Tschö, Auge