Act 3 Quest Progress/Gamestate rollback. (Big Bug)

On Act 3 Cruel... After "Complete the Trialmaster's Challenges"... I portal'd back but woke up on the Riverbank. Took player portal from there and came back to Ziggurat Encampment and proceeded to the Temple of Kopec. Defeated the boss... The Gate opened in the encampment... And when i entered it brought me back to the Riverbank. But now upon portalling back... The Gate is gone. And my quest progress is back to "Travel to the Drowned City" and "Complete the Trialmaster's Challenges". This is a significant step back in progress and loss of time.
This type of thing has happened in other play throughs, but seems to resolve itself. The only thing that had been a consistent issue that was similar was joining someone in a non cruel act... Then when trying to come back it would bring me Riverbank. But again... Was able to return to normal gameplay with no noticeable loss.
This however is quite frustrating.

Act 3 Cruel to be specific.