If these have been mentioned, I apologize.
Seitung Province
A lot of the Shrine Guardian chests are bugged, most of them being ones where you pick up a rock. The following are ones I have noticed I couldn't complete.
Hint: Watches the Aetherblades near the monastery
Hint: Plays with drakes
There's probably more than just these two.
New Kaineng City
Some of the Jade brotherhood graffiti is not interactable and there don't seem to be enough in the city at one time (maybe intended and not a bug, I don't know)
Echovald Wilds
Unable to start the crypt events if it has already been completed on a map instance.
Cannot start Sigga's black moa quest even though the event icon shows up. Sigga is not interactable.
The archery contest event chain doesn't seem to ever be active
I haven't done much in Dragon's End so haven't found anything there yet.