I have heard SNOs in China mention low success rates on transfers before.
I have a script here that you can use to see the success rate of your node for uploads and downloads.
A low success rate is usually caused by high latency between your node and the uplink/customer. Unfortunately the interconnects with China aren’t always as low latency as you would like. One problem is that there are only three international entry points in Beijing, Shanghai, and in Guangzhou. These will be significant choke points in the international network. Furthermore, there is a lot of filtering and deep packet inspection in place in those locations to filter the international internet. This is not so much a problem for the network speed inside China, but significantly slows down international traffic.
All of this to say that for now, you may see low success rates. But if more Chinese customers get onboarded, your node will likely be first in line. Since at that point the rest of the world is at a disadvantage for those transfers.