Did you receive the JYH one? Then you must have bought it recently. I asked some Chinese friends, and one of them mentioned they also got the JYH with their purchase in May. Topping might have stopped using the Kailiyuan power supply.
Yes, bought sometime in June.
Just saying that more people with Kailiyuan adapter will have to come out to say that they have similar problems, for your speculation that the entire Kailiyuan batch has problems to hold water.