Hey Smoothcriminal and Crossing,
Thanks for the report! I can confirm that I see the same behavior and that it is in fact a bug.
I went ahead and reported this to the developer to fix.
Can confirm it's still broken, I started having the problem on my quests in Two Crowns area, beforehand it was fine, but now all that I have is "Unknown Location"
I am having these issues in the Two Crowns area with my Elf and in the Hellswamp with my Warborn. I haven't found a pattern to it yet. When I get a new quest it will sometimes give me an arrow and a map marker and sometimes not. Once I complete the objective and it is time to return it is also random whether I get a marker or not. When I open the quest description the map button is greyed out and won't show me anything when I try to click it.