@BlindGuardian router more should be fine, as it is the dhcp server. Not you can't use another device as DHCP server in this setup.

@KevinCH out of interest how do you know it's now working? I am looking tomuse ethernet backhaul but have no idea how to tell it is functioning.

@BlindGuardian no simply reboot all the decos after the router has come up, should sort it.

@BlindGuardian I personally have found power lines really unreliable regardless of brand. Try an M5 if it doesn't work out return it... Just look out for this as its not obvious until you scratch...

@BlindGuardian that's the challenge I am grappling with. To be fair I like there app and it does just work save for this stupid issue. I haven't tested throughput but that's less of an issue for me....

Also can you ping your developers? I'm concerned that they are stuck on their own subnet without any wan access... Given the time taken to respond. As you said they were contacted months ago, may be...