ARP table on HA pair

[#1]

Working on upgrading older 1400 series appliances with new ones.  Ran into a problem with the first passive upgrade.  My question is, why does the ACTIVE appliance ARP table show Passive Interface IP's as <incomplete> no MAC address on both the LAN1 and the HA interfaces.  Passive ARP table shows IP's and MAC addresses for either LAN1 or the MGMT interfaces, only.

Any ideas?  Appreciate any help.

[#2]

This is what it looks like.

? (10.20.5.12) at <incomplete> on LAN1
? (10.20.16.1) at 00:00:0c:9f:f0:01 [ether] on MGMT
? (10.20.5.14) at 3c:ec:ef:72:b4:21 [ether] on HA
? (10.20.5.5) at 00:00:5e:00:01:08 [ether] on LAN1
? (10.20.5.14) at <incomplete> on LAN1
? (10.20.16.3) at 28:6f:7f:7e:a1:e9 [ether] on MGMT
? (10.20.5.54) at <incomplete> on LAN1
? (10.20.5.7) at <incomplete> on LAN1
? (10.20.5.12) at <incomplete> on HA
? (10.20.5.8) at <incomplete> on LAN1
? (10.20.5.3) at 28:6f:7f:7e:a1:e9 [ether] on HA
? (10.20.5.1) at 00:00:0c:9f:f0:01 [ether] on LAN1
? (10.20.5.29) at <incomplete> on LAN1
? (10.20.5.3) at 28:6f:7f:7e:a1:e9 [ether] on LAN1
? (10.20.5.1) at 00:00:0c:9f:f0:01 [ether] on HA
? (10.20.5.8) at 0c:c4:7a:b4:1f:ee [ether] on HA
? (10.20.5.9) at <incomplete> on LAN1
? (10.20.16.2) at 28:6f:7f:7e:9e:47 [ether] on MGMT
? (10.20.5.2) at 28:6f:7f:7e:9e:47 [ether] on HA
? (10.20.5.6) at 00:00:5e:00:01:08 [ether] on LAN1