Tests done; first one, the link from the source does interfere. Links like that can't be on a top level thread, that is why it doesn't show on the general feed.
But both not showing in the UI are because they are longer than 240 characters.
If you are a new premium or newly updated, try login out, clearing caché and login back in.
I'll report this bug n.n
Will do that. I'm a new premium user.