That particular trophy is meant to be obtuse. You can come back to the area to get it at any time, though leaving the map does reset progress towards it. The extra dialogue is there as an indicator that you're making progress.
Thank you. After I freed the trapped NPC - the teleport I had used to enter the maze has a different destination. So I concluded that the maze cannot be entered again.
If I can complete it any time, then I am less worried and will visit the maze at a later time.
Thank you again for the fast help and confirming that this was progress message.