I have enable in my routerboard 532 arp reply-only ether2 interface (server dhcp) for all client link only in dhcp mode and work ok , if enable also hotspot (interface local ether2) arp replyonly mode not work 
and client link also in ip static mode…any idea???..Thanks!!!
Hmm, I am not sure I understood you correctly, but did you do:
/ip dhcp-server
set x add-arp=yes
where x is the number of your DHCP server you want to work with interface with reply-only ARP.