on threads list pages, you can click the x next to a topic with new posts to reset your last read and stop “tracking” it
this only shows up in desktop mode for now. i can’t find it into the mobile page… yet.
this also works for PMs, and any PMs you do it to will stop showing up on your top bar as in “Inbox (1)”. they will still be bold in your inbox. you can click on them to start tracking it again