Batista! He rises!!
It's nothing more than X's and O's.
Whether the goods are contraband is your determination.
US laws has no effect on international trade between nations. The US applies pressure on it EU trading partners and Canada to go along with sanctions...but China is not in the EU and along with Russia has followed its own path in trade with Cuba.
No way the US would abide by Chinese law outside of Chinese territory and without an agreement or treaty.