FortiGate v6.4.x, v7.0.x,v7.2.x, v7.4.x, up to v7.6.2.
Starting from version v7.6.3, the SSL VPN tunnel mode feature is replaced with IPsec VPN tunnel, allowing users to configure IPsec over TCP port 443 for secure communication, providing a more flexible and reliable VPN connection method.
diagnose debug disable
diagnose debug reset
diagnose vpn ssl debug-filter src-addr4 x.x.x.x
diagnose debug application sslvpn -1
diagnose debug application tvc -1
diagnose debug console timestamp enable
diagnose debug enable