Block traffic from LAN to PC with active SSL VPN connection

On FortiGate whe have option

config vpn ssl web portal edit full-access set exclusive-routing enable

Remote client (win) connects via SSL-VPN FortiClient to FortiGate (version 6.0.6). We have tested client connectivity with ping to the local subnet and it doesn't work as expected. Clients LAN network is not reacible. BUT another device from same LAN can still RDP to this client.

We consider this as a big issue. Device using FortiClient should be isolated from local subnet, during SSL VPN is established.

Does someone has experience how to easily block traffic from LAN to client during established SSL VPN?

Thanks

Janez