Hello,
This Sidequest aka. Secret Quest is STILL bugged. Solutions do not work. And I don't find anybody on that quest since months. Firstly reported this bug 3 years ago.
It was on the "To Fix List".
It still has not been fixed.
It really bugs me out.
I just wanna complete the Quest.
Please, either offer Completion Rewards to Players experiencing this Bug, or fix asap.
Thank you.
(As it is a somewhat rather famous bug, also posts on reddit explaining the bug, I shall not go into further detail about the bug itself - it's perfectly described on reddit and many other places).