I use NETransparentProxyProvider transparent proxy the outbound data ports 80 and 443, at the same time using CocoaAsyncSocket third party open source libraries for data forwarding At first, handleNewFlow will be called normally, but after running for a period of time, handleNewFlow will not be called again, and the system will not be able to access the Internet unless the vpn is disabled By checking the terminal app log, I found that handleNewFlow will not be called again when the following information is displayed. # Domain=NEAppProxyFlowErrorDomain Code=1 "The operation could not be completed because the flow is not connected" UserInfo={NSLocalizedDescription=The operation could not be completed because the flow is not connected" #