Fortiswitch_standalone-to-trunk port cisco

Hi

I have a cisco switch with trunk port connected to a fortswitch in stand alone mode, i am not able to pass the traffic between them, i have this config 

EXAMPLE:

CISCO

inter gi0/1/1

switchport mode trunk

switchport trunk allowed vlan 50,10,100

#fortiswitch in standalone

config switch interface

edit port4

set allowed-vlan 50, 10, 100

next

edit port5 

set native vlan 50  (acces port)

next

end

i connected a PC to port 5 and i am not able to do ping to gateway. 

Some have configured something like that ?? can you share a KB

FortiSwitch