Still not working.
You left a private topic without having read the most recent reply, which makes your private topics marker perpetually unread. I’ve fixed this for the next update so that topics you’ve left don’t count toward unread topics.
Also, not exactly the right place to post this, but I’m seeing new issues with the unread posts marker. It’s the opposite problem now, where the marker is cleared on the main page even thought there’s still unread posts in the subforum.
It’s always worked this way. If your session ends, discussion markers are cleared. Topic markers aren’t.