I was trying to complete the final warning quest, but it wont progress past step 3, where it is supposed to check if you have the "Shadow Legion Orders" consumable in your inventory or something. Abandoning the quest/deleting and reacquiring the consumable (the quest will trigger the boss to spawn still) didn't do anything. It seems a few people are running into the issue since the guardian games patch. Hopefully this will get on the list of known issues and fixed at some point soon.