This is how I got to the bug
Steps to reproduce
1. Open Quest Journal "L"
2. Make sure "Quest Tracker" is ticked
3. Go to "Achievements" panel
4. From the drop down, choose "Daily Wipe Out"
5. Tick any of the available achievement quest that is shown. (Mine was "Abandoned Robot Annihilation")
6. Make sure the quest has appeared on the tracker window.
7. Go and finish the quest.
8. Notice that after finishing the quest the tracker window still shows you the quest.
Even after finishing the quest, the tracker still shows it.
Finishing the quest should remove it from the tracker window.
1. I think the problem only occurs with Daily Achievement
2. Now I cannot put any other achievement quest on track because only one is allowed.
3. Moreover, even after the daily quests has been reset, the tracker still shows the 'stuck' quest (See screenshot)