Continued FortiClient-VPN-Session after User Logout

[mra]

Hello everyone we have a problem with the FortiClient. Short summary: FortiClient holds the VPN-connection, although the User created the VPN-Connection is logged out. Other Users can log into the Windows System and are still connected with the VPN-Tunnel of the other user. Full problem: We have created a IPsec VPN so external Users can login. External users share their workplace, which means multiple users on one PC/Workstation. We found out that, if User A successfully authenticate and creates a VPN-Tunnel the Tunnel is still present after the User A logged out from the Windows system. User B can then login into Windows and finds the still working VPN-Tunnel in his environment. He then can use the same policyrules like User A. Does anyone know how to configure the FortiClient, so the VPN-Session is killed during a user logout?! Best regards Mike