Traffic between VLANs: Fortigate 40f & Fortiswitch

[Aqualectra]

I have the following topology:
A fortigate40F & a Fortiswitch; 
I have a fiber connection coming into the switch, because I do not have sfp on the firewall.

What I want to accomplish is that my firewall communicates to my core network(VLAN102), while I have a port on the switch that is in VLAN103 so that the client that will reside on port 5 of the switch is able to communicate to a server that resides behind the gateway of my firewall ( VLAN102).
I want to protect the traffice with vDoms, one for the VLAN102 (root) and one for the VLAN103 (internal).

I have tried the following:
- create 2 vDoms
- create 2 VLANs and assign each to one of the vDOMS
- create vDOM links
- create static routes between the vDOMS ( using the vDOM links)
- assign the VLAN on the port of the switch where the client is connected.

- I am unable to view the ports/switch from the second vDOM, only on the root vDOM
- the client is unable to even ping the IP that is one the same vDOM & VLAN.

any clue where the flauw in my config is ?