China is very affected and has been tightening the screws hard. The situation really blew up when a Chinese actor was lured to Thailand, kidnapped across the border and forced to work in a scam center:

https://en.m.wikipedia.org/wiki/Disappearance_of_Wang_Xing

There was even a Chinese blockbuster movie about this:

https://en.wikipedia.org/wiki/No_More_Bets

But the scammer choose lawless places like Myanmar for a reason and while China can exert pressure on individual bigwigs, they can't stop those small enough to fly under the radar.