FYI, I find exactly the same issue . . . even when connected to the same router, I can ping the Control unit (192.168.1.227) but NOT the Radio unit (192.168.1.228). Otherwise, all is working OK, and I can reconfigure either unit via the web interface, so I only want to do the ping to test network latency. This happens when I have both units at my remote location (with a Verizon ADSL router) and with both units at my control point (with a Verizon FIOS router). The ping watchdog even works OK, so the Radio unit can make a ping, it just does not respond. I am using current hardware and firmware (purchased in mid-2018).