r4nchy if you're referring to the slug not being included after the discussion ID, that's intentional.
I think the reason for doing it like that is that it acts as a kind of link shortener.
The link should work fine even when the slug isn't included, Flarum will automatically expend it when clicked.
If you're referring to no post number at the end of the URL, that extension doesn't have the ability to share links to specific posts/page, it always shares the discussion itself.