Apart from the small problems that I have written about before, I have only one major problem with my new Duo 4K: The WLAN connects, but it never gets an IP address or a gateway. I have tried with DHCP and with fixed IP addresses (in the latter case there just is no traffic). On the router, there is nothing in the log; it is as if there is no connection at all. The MAC address of the Duo is not registered in the router log, nor in the WLAN connections.
I fear a hardware error, but cannot really believe it. I am going to get hold of another router and see if it works with that one.