Dont know what planet you are from , but there is no communist regime. Nor has it ever been any communist regimes.That is also priceless statement.
Chinese support Pakistani sponsored terrorists in India but fight the same in Xinjiang. They support communists of North Korea but fight the Communists of Vietnam. They have dual policies wrt to Shan and Kachins. In Sudan they will support any terrorist which gives them oil and supply weapons to them to fight other terrorists. They will also support Taliban in Afghanistan but fight them inside Xinjiang.
Your support of earstwhile commies is stark and instinctual. I do not say it is bad... it appears to be blind...
Try not to confuse autotarian regimes with communism as a utopia.
China supports whatever the regime who can benefit her. She has always been pragmatic in foreign policies.