According to Symantec https://www.symantec.com/blogs/threat-intelligence/security-vpn-ios-macos Symantec has uncovered a security issue with iOS and macOS that can result in network traffic circumventing VPN tunnels. "The issue allows third-party developers to develop applications that could bypass the VPN client set-up, resulting in any traffic or data originating from the application intentionally or unintentionally being sent across unsecure channels," said Symantec's Qubo Song.