Pretty much what Coldshade says, but trial toons might be limited from doing these unlock scenarios.
Here, a guy had the same question as you and he had a phasing issue. The questchain wasn’t given to him on his trial character so… likely restricted to them.
You’re welcome to try your luck of course 
(PS: the OP of the thread I linked is my lookalike but with a male toon. Coincidence?)