I have a 3 Pack of Deco P9. Installed one on the attic (home office), one on the ground floor and one in the basement.

The units on the ground floor and top floor function without issue. The one in the basement is a challenge. WiFi does not reach the basement (it s concrete which is why I got the P9) so I am expecting it use the Powerline connection instead. However, I am having challenges getting it to work.

I am not able to initiate setup in the basement: since Wifi does not reach there I cannot use the app on the phone to configure it. So I configure it on the ground floor and once I am done I unplug it an reconnect it in the basement. It will always go to the red led, although sometimes it will be on white led for some time and then I can connect 
 

- If i configure it on ground floor I can see it shows Wifi + PLC

- The ONLY way I can get it to work reliably is by ethernet backhaul (but that means a wire sneaking over the floor and down the stairs, cannot be permanent)

- If I can connect in the basement, speed is a mere 2-3 Mbps. When I use the backhaukl it is 90+

I tried differrent sockets, no diffference. How can I connect over Powerline?