So, it's been a year and a half now, and this glitch has not been resolved yet. I just started a New Journey + playthrough, and now I'm on Dathomir where it's showing at least one missing chest. So far, I've only personally confirmed one missing from the Swamp of Sacrifice. There are three chests in the Swamp, and I have visited all three locations a few times, confirming that they are all, in fact, open. However, it only shows 2/3 open on the map, making it impossible to count Dathomir as complete. I've yet to determine if this is affecting Zeffo or any other locations at this time.
