This particular replication attempt appears to be Chinese, yes. But it makes no sense for Chinese researchers to be deliberately faking the replication of some unrelated Korean scientists’ supposed fraud (which makes no sense to be fraud in the first place). What could they possibly gain from it aside from the ruination of their own reputations as well?

I could believe that LK-99 is not actually truly classically superconductive, but instead has a bunch of weird properties that suckered its creators into thinking it was. It seems unlikely but eh, maybe. Weird things pop out of the universe sometimes. But it’s really implausible that this is all a deliberate fraud. If you’re going to make fraudulent claims about inventing a new kind of superconductor the last thing you’d make up is something that anyone can make for themselves with a few basic ingredients and a pottery kiln. That ultra-high-pressure room temperature superconductor is the perfect counterpoint - it was so hard to replicate that it took ages to show it was fake.