Troubleshooting Tip: FortiClient does not connect on Ubuntu 23.04 without any error in return - goes back to connect continuously

[Umer221]

Description	This article describes how to troubleshoot an issue where FortiClient tries to connect, but ends up not connecting and returns to the connect screen without producing any error.
Scope	FortiOS, FortiClient, Ubuntu 23.04.
Solution	Make sure FortiClient is configured properly on FortiGate by referring to the : SSL-VPN full tunnel for remote user - FortiGate administration guide. If all the configuration is correct and FortiClient on the devices running an Operating System other than Ubuntu 23.04 can successfully connect, follow the next step to resolve an issue specifically related to Ubuntu 23.0.4. Use the following article to disable IPv6 for the NIC 'FortiClient SSL VPN' and the rest of the NIC enabled during SSL-VPN connection: Disable IPv6 in Ubuntu.