I have just help a customer, with a problem with his FortiClient.
The Forticlient did connect successful, and everything looks good, but there are no traffic iis recieved.
The OS of the customer where Windows 11.
The solutions where quite simple, just uninstall this microsoft update: KB2693643
Read more about the error here: https://community.fortinet.com/t5/FortiClient/Troubleshooting-Tip-VPN-SSL-connected-but-no-IP-address-in/ta-p/248143