VPN with two internal subnet : how to ?

Hello,

I'am facing with a "strange" issue with a Fortigate 200e firewall (firmware 5.6). We use VPN for a long time now. One site-to-site and another for an access with Forticlient. Both works fine.

But this fortigate is behind one internet connection and provide internet access for 3 subnet separate by VLAN in the same building.

                                 |--> subnet 10.x.x.x/24

WAN --> Fortigate -->|--> subnet 172.x.x.x/24

                                 |--> subnet 192.x.x.x/24

Our network is the 192.x.x.x and VPNs WAN to 192.x.x.x/24 is working fine. But when I make a new VPN connexion (for forticlient remote access use) to subnet 10.x.x.x the conenxion fail. I create the VPN connexion with VPN Wizard and remote access template but the client can't connect. There is no log in WEB interface's VPN envent, but I have some trace with the CLI.

I have two log one with a non working remote access and one with a working remote access. Both use the same username/password but the shared key is diferent.

Here the file with two logged connexions : 

Why the remote access refuse to work with any subnets other than the 192.x.x.x one. And how the make it works with others subnet ? Thanks ;)