Have you still some sales in China or all chinese sales have stopped ?
Regulation changes regularly in China to control more and more strictly apps business.
https://www.reuters.com/world/china/china-enforces-new-filing-rules-smartphone-app-stores-2023-09-27/#:~:text=The%20country%20now%20requires%20mobile,need%20to%20be%20taken%20down. : This article explains the Apple could be forced to remove many apps from its Chinese appstore. Is it your case ? have you a mean to ask someone in China if your app is still accessible ?