Bugged for me too.
My objective says “Travel to the Priory Archive in Lion’s Arch”.
I map in, and Gixx is there, and just says “Can you be helped”.
I walk to the star, and a chat between Sieran and Kekt pops up.
When it finishes (regardless of if I skip or wait), it still has the star in the same place with the same objective, and there is no exit instance button.
I’ve relogged my client, and tried it about 5 times so far, really annoying. I was very dissapointed to discover this is such an old bug, fix it up please developers!