Have tried starting the adventure before the zone buff was active and finishing while active (no double)
Then started a new one while buff was still active and finished with buff time still left and still no double. 14 is just high amount, double should be 18 or 28. Have also done many lootspots while buff active and no double on those either. even the beans in that reward were 1700 which at double should be 3400. and the platinum shows 6000 which is the normal amount