Fortigate 100E - Cannot access port of IP Wan after upgrading from 5.4 to 5.6

Dear all,

I have a public IP of the ISP, using NAT to one IP of DMZ Fortigate 100E.

Example:

Public IP of the ISP: 1.2.3.4 Nat to Internal IP of DMZ port Fortigate 100E 192.168.1.2 (myserver.mydomain.com)

Policy: LAN to WAN1, LAN to DMZ, DMZ to WAN1, WAN1 to DMZ.

When I used firmware 5.4, I was in LAN and ping myserver.mydomain.com (1.2.3.4) OK, and access myserver.mydomain.com:port (ex: myserver.mydomain.com:1000) OK.

But after upgrading to 5.6, I can not ping to my server myserver.mydomain.com and I can not access myserver.mydomain.com:1000.

Any help for me?

Best regards and thank a lot.