forticlient for ISO get DNS mismatch with setting on fortigate

[Supercalar]

I found forticlient for IOS get DNS form local Mobile Phone. I have set up DNS on fortigate but it not match with forticlient for IOS.

More info

FortigateVM Firmware 5.6.3

Forticlient for ios version 5.6.6.0194 

Please help me verify this issue

[tanr]

Are you doing split tunneling?  I believe I ran into something similar a while back - https://forum.fortinet.com/tm.aspx?m=155295.  I didn't find a solution at that time, besides turning off split tunneling.