The sorting works fine and, in my opinion, as it should. Stickies sorted by creation makes sense. Everything else sorted by activity.
That being said - it seems there are a number of users here confused by the sorting. That creates the question: Why?
It must have something to do with the design.
One thing’s for sure: Stickies are not clear enough. It’s only that one little pin, while in the old forums they were highlighted.
And then the “xxx months ago” below the thread title could be misleading for some who think this could be the last post?
Also, the right column does not have a headline labeling it as “most recent post”.
Do we / the admin have any way to adjust the design?