Same bug happened to be today. Hoad to go to the far west of the instance for a green quest star to appear on Gixx. Fist few times i thought it was a bug and logged out and back in again, since after you talk with siera, the quest star dissapeares from above her, but remains in the same spot on the minimap. I don’t think this works as it should, since I don’t remember having this problem from the first time i did this quest chain.
The content designers should really take a look into this, since it is a verry old issue.