Hinterlands undiscovered quest bug near astrarium

I started a second playthrough, and I encountered a strange bug in the Hinterlands that I didn't notice (or probably didn't get before) in my first playthrough. There is an exclamation point (!) on the area near the astrarium east of the starting camp. I've read that an enemy mob is supposed to spawn on that spot and drop a bag containing the quest trigger. My problem varies from the mob spawning, but doesn't drop the trigger, to the mob not spawning on the spot at all. If anyone has an answer, I'd appreciate it. ☹️ Thanks.

EDIT: I should mention that I've tried zoning and reloading saves. Neither solved the problem.