I’ve finished the main campaign through to the second round of “Deeds of a Champion.” Playing on Penitent. Then I did Pit of the Artificer on level 20 3 times – it said it unlocked Torment difficulty. I can also see in my Challenges UI that it says “Tormented Challenger 1” is completed.
But I’m still unable to lock Torment 1 difficulty, either on the character selection screen or at a difficulty picker in any city.