Redo the task. I have done that. I replayed the entire main quest of High Isle on another character in the hopes that it would unlock. But I fear account-wide achievements are preventing this solution. This worked before when I had many “scout” and “conqueror” achievements related to dungeons that wouldn’t unlock on my main character. But with account wide, what is the recommended solution now? The achievement is unlocked on all characters, but not on Xbox.

All I get from customer service is that they cannot “grant or restore” achievements. I have noticed that when I go to Xbox.com to look at my achievements there are multiple achievements from this game are not there at all. It’s not that they are just locked when I think they shouldn’t be, but it’s like they don’t exist, locked or unlocked. I know they are achievements because I see them on the console and on websites like True Achievements. I don’t know what this means or why this would happen, but I have a feeling this is why so many achievements don’t unlock for me on this game. Has anyone else experienced this?

The same thing is happening with the Galen achievements. Did your High Isle ones ever pop in the end?