SNMP ARP table query

Hi, i have recently upgraded my LTM to version 12.1.3 and now im not able to get the arp table via SNMP. Before the upgrade i used to query ipNetToMediaPhysAddress (1.3.6.1.2.1.4.22.1.2) to get the Arp table, after the upgrade when i query this OID i get a "IP-MIB::ipNetToMediaPhysAddress = No Such Object available on this agent at this OID".

The LTM is not responding to this OID? Weird, I found out after doing a SNMPWalk that this OID doesnt exist on the 12.1.3 version, instead there is a Private OID (ipNetToPhysicalPhysAddress) that shows us the ARP table but only for the Self IPs and VIPS IPs. How can i get the Arp table of the servers that are connected to my LTM trought SNMP or API?