Apps on Android phones not working via Fortigate 30E

[msid]

I have setup 30E model at my home. the set up as follow

----Fiber to Home (dhcp) -----Fortigate 30E (WAN port) ------LAN port 1-----WIFI AP---Android/IPAD/IPhone

I am able to browse internet and using app from IPAD and iphone.

However only able to browse internet via Android phone but not able to use any app (like facebook, gmail, yahoo etc)

I dont have web filter subscription and that is turned off at this moment. 

Any ideas why ?