Unloading older shipment is not same as making new orders. I never said China won't unload older shipment. Even India has some older Iranian oil coming even after sanctions ended as the refineries and storage are sometimes full and request delay of arrival of oil by 1-2 weeks. Moreover, distance between China and Iran is 9000km which will mean it takes 2 weeks for one-way trip. So, oil coming now must have been ordered before sanctions
India has regularly imported 300,000 BPD oil from Venezuela. India never stopped any Venezuelan oil contract.Indi even supplies diluent to Venezuela to help them process more oil.
You are assuming that ships are only tracked by trackers. Reality is that the ships are also tracked by radars, satellites and drone surveillance. Since USA has bases in Arab peninsula, it regularly does surveillance to check if Iran is sending any oil tanker outside and then follows its movement periodically and at choke points like Malacca straits. You must be a real retard if you think that anonymous and random ships can simply move around in Malacca straits or in other countries' territorial waters without proper permits
Bottom Line: Please provide me authentic news that China has bought Iranian oil after sanctions.