Hosts in registeration or remote vlan can't resolve srv record _bradfordagent._tcp.reg.example.com

Dears when the hosts in registration or quarantine vlan persistent agent can’t communicate to fortinac because can’t resolve srv record and retrieve info about fortinac ip address but it retrieves portal and i think it is default in fortinac

and when i search in this file i can’t find resolution for srv record except the portal.
cat /var/named/chroot/etc/domain.zone.reg 

cat /var/named/chroot/etc/domain.zone.rem

so how can resolve this problem as when i search i find that for isolation VLANs it should there is record hosted locally in the fortinac