If you have determined that network traffic is not entering and leaving the FortiWeb appliance as expected, or not flowing through policies and scans as expected, you can debug the packet flow using the CLI.
For example, the following commands enable debug logs and the logs timestamp, and set other parameters for debug logging:
diagnose debug enable
diagnose debug console timestamp enable
diagnose debug application proxy 7
diagnose debug flow show module-process-detail
diagnose debug flow trace start
diagnose debug flow filter server-ip 192.0.2.20