@NOTHappyW_M9 I was not aware that the decos had a primary and secondary lan-port and there no mentioning of this in the manual either so I haven´t given any thought about what ports my devices are...

@Alexandre. Heres a drawing of my setup. I "only" have a 250/100Mbit internet connection and when i run a speedcheck om my PC i get 250/100Mbit so no issue there. My problem is when i send files...

@Alexandre. Nice! My problem is low transfer speeds between devices connected on ETH to different decos. Would it be possible for you run a iperf3 test with 2 pc's connected to ETH on separate decos...

I've been having problems with slow lan-transfer speeds since day one with my 3 M9+ and not expecting this to get fixed anytime soon if ever. When doing a google-search there is plenty of other users...

Any updates on this? I've been having the same problem for months now. I have 2 devices wired to different Deco's in the same room maybe 6m apart. Both devices say there connected with 1.0 Gbps but...