Weird route behaviour in 5.6

Hello, We manage several fortigates and this is the first i am clueless about this issue. I am UNABLE to reach the whole DMZ from the Internal LAN. Wan -> DMZ Works DMZ -> Internal Works (it was a test) LAN -> DMZ doesn't work. Policy was a plain one: Internal -> DMZ all open. We have tried a single pc connected to the internal just to exclude other network devices in the lan. Looking at the Flow debug it seems traffic goes toward default gateway to internet. Even a traceroute, the first step are * * * * I even tried to add static routes to client and it doesn't work, firewall dmz ip is reachable!!! I don't know what else to look at since this is something I do for years and it's easy to implement.