We got more information about this.
2021-05-07 14:09:31.538353+0800 Hello[1986:2515251] [] nw_path_evaluator_create_flow_inner NECP_CLIENT_ACTION_ADD_FLOW 0A158B95-F5ED-4E9B-8D68-4BDC211744F9 [48: Address already in use]
2021-05-07 14:09:31.538839+0800 Hello[1986:2515251] [connection] nw_endpoint_flow_setup_channel [C16.1 123.125.102.213:5222 in_progress channel-flow (satisfied (Path is satisfied), interface: en0, scoped, ipv4, dns)] failed to request add nexus flow
2021-05-07 14:09:31.541714+0800 Hello[1986:2515251] [] nw_path_evaluator_create_flow_inner NECP_CLIENT_ACTION_ADD_FLOW 81D30F6B-0642-49B1-A0F4-C756CA26B1F9 [48: Address already in use]
2021-05-07 14:09:31.541917+0800 Hello[1986:2515251] [connection] nw_endpoint_flow_setup_channel [C16.2 123.125.102.213:5222 in_progress channel-flow (satisfied (Path is satisfied), interface: en0, scoped, ipv4, dns)] failed to request add nexus flow
2021-05-07 14:09:31.543370+0800 Hello[1986:2515251] [] nw_socket_copy_fd_wrapper called with null protocol
2021-05-07 14:09:31.546335+0800 Hello[1986:2515251] [] nw_socket_copy_fd_wrapper called with null protocol, dumping
Thread 6 Queue : com.apple.network.connection-16 - https://developer.apple.com/forums/content/attachment/116803ca-9b25-4420-b9ab-25d5bd7215bd