It sounds as though your VPN connection secures all networks and possibly that you have IP overlap i.e. Your LAN IPs match the remote LAN. Have not use the Sonicwall Netextender, but see whether you have an option to not set the VPN IP as the default route/gateway. Using NetExtender. NetExtender is an SSL VPN client for Windows, Mac, or Linux users that is downloaded transparently and that allows you to run any application securely on you company’s network. Using Point-to-Point Protocol (PPP), NetExtender allows remote clients seamless, secure access to resources on your local network.
SonicWall Mobile Connect™ provides users full network-level access to corporate and academic resources over encrypted SSL VPN connections. The client provides anytime, anywhere access to critical applications such as email, virtual desktop sessions and other macOS applications. REQUIREMENTS: SonicWall Mobile Connect is a free app, but requires a concurrent user license on one of the following SonicWall solutions in order to function properly: • SonicWall Next-Generation Firewall appliances including the TZ, NSA, and SuperMassive running SonicOS 184.108.40.206 or higher. • Secure Mobile Access (SMA) 100 Series appliances, formerly called SonicWALL Secure Remote Access (SRA), running 7.5 or higher.
• Secure Mobile Access (SMA) 1000 Series appliances, formerly called E-Class Secure Remote Access (SRA), running 10.7 or higher. For more information on SonicWall Secure Mobile Access and Next-Generation Firewall solutions, please visit www.sonicwall.com.
• macOS High Sierra Compatibility – Mobile Connect is fully optimized for the latest release of macOS High Sierra. • Network Extension Support – Mobile Connect now leverages Apple’s current VPN framework, called Network Extension, to allow for more reliable VPN connectivity on macOS devices. After upgrading to the 5.0 version, Mobile Connect may need to be re-provisioned, including updating VPN connection configurations and certificates (if applicable). • Touch Bar Support – On supported MacBook Pros, the Touch Bar at the top of the Mac keyboard adapts to what you're doing and gives you intuitive shortcuts and app controls when you need them. Mobile Connect now supports Touch Bar for all supported Mac devices. • Touch ID Support – Touch ID may be used as a seamless alternative to username and password authentication if allowed by the VPN server.
Requires compatible server with configured Touch ID policy, as well as a Mac with a configured Touch ID sensor. • Global HA Support – Mobile Connect contains updates for the global high availability and disaster recovery capabilities for VPN connections to SMA 1000 Series servers running 12.1 or newer firmware. See the release notes on the SonicWall web site for more information. • 4.0.16 31 Mar 2017.