On my UI, I have a completed quest and it's content (information, text) stuck on my screen. The quest is specifically "The Journey Home: Humanity's Final Beacon".
This quest has already been completed on my end. There is no way to untrack / track it.
This is still a problem, and it persisted until I completed the entire questline at The Watch. The tracker shows it as "Complete the <i>A Safe Haven</> questline" as shown in the screenshot.