I do have this problem also. I have configured the policy correctly but still there is no access to each other. One thing what I did observe was that for every vlan created on the fortigate there is a connected route under the Routing monitor. But interesting the route to the sslvpn is not present. When I do a route lookup for example, destination 10.10.1.4 (sslvpn IP address) from the LAN gateway 172.16.16.1, the hit I got was via the default route 0.0.0.0/0 via internet gateway! BUT this leads to nowhere since there is no public IP address for the destination and it will just end on the cyberspace somewhere.
So what do you guys think if I create a static route from LAN to the sslvpn subnet, will then this help!
Has anyone succeeded with this and how?