Pl refer following kb.
https://kb.juniper.net/InfoCenter/index?page=content&id=KB30584
under global config, add following to make dhcp working.
set forwarding-options dhcp-relay forward-only-replies
https://kb.juniper.net/InfoCenter/index?page=content&id=KB30584
under global config, add following to make dhcp working.
set forwarding-options dhcp-relay forward-only-replies