Sonicwall Customer Service Issues

One of our clients is experiencing a bandwidth issue with their 50 Mbps Syscon link from the ISP. During troubleshooting, speed tests were conducted with and without the Sonicwall, showing varying download and upload speeds. Attempts to resolve the issue included disabling/enabling IPS, connecting Syscon link from the X2 to X1 interface, and considering a Sonicwall reset. After backing up the settings, a hard reset was performed on the Sonicwall, and the link speed negotiation was manually set. Efforts were made to introduce a switch as a mediator between the ISP link and the firewall, but the customer was not open to changing the switch connections for further troubleshooting. Sonicwall technical support recommends connecting an intermediate device like a switch for testing. The customer seeks guidance on deploying a switch between the ISP and Sonicwall with a network diagram and how to troubleshoot the issue efficiently with the switch in place.