Client Local IP address passtrough tunnel with External DHCP over IPSec configuration

Hi! I must to work with external DHCP over IPSec faster as i can cause using range from Fortigate is causing a lot of DNS problems in my company. I tried so many things, DHCP works fine for some clients, but in some cases the client get his own local IP Address Trough VPN, the Forticlient shows the IP assigned from DHCP but in IPSec monitor shows me the client Local IP Address, sometimes the client connect with two IP Addresses, his own local IP and the assigned DHCP IP, that create two phase2 selectors too.