Try using it on the deposits of the one AI I have contact with, "action is locked" regardless of if they have an extractor or not, Get "luxuries can be traded" treaty, action still locked. Ok, they are also mercantile, Caralans, maybe it just doesn't work on other mercantiles?
Try it on my own stuff, inside my own city, that can build Artisan Quarters on them "Action cannot be done as territory isn't owned.
Phoenician is a scam.
Culture - Nubian
Domestication is researched
Cant use power investor on the horse resource tile to create extractor
It shows that resource is not discoverable yet. I can build extractor through the city but not the ability.