Trouble Pinging Outboard Gear With Aggregate Device

On macOS Sierra (latest update) running Cubase Pro 9.0.20, trying to use an Aggregate Device consisting of two (2) MOTU 16A’s both connected to the Mac by Thunderbolt, and connected to each other via cat6e network cable, in ordet to connect my growing outboard collection. My issues are with getting my outboard on the 2nd 16A connected.

It seems that when I’m at the network connections (F4), I can’t get the ping to work, or even show an indication that it’s going through. However, when I add the external effect as an insert and try to ping it in the project screen, it does show that it’s sending and receiving correctly, however, the latency time just stays at 0.00. I really have no idea what the problem is, and it’s like that no matter what device on the 2nd 16A I try to ping to. Does anybody have any suggestions or have a work around? This has been very frustrating and i’ve been trying for days to find a solution, but to no avail.