Hi,

I have a EE broadband router which used to be cabled to a Deco M9+ (as the main device in router mode) with 2 other M9+ and an M4 all with Cat6 backhaul connecting them... Everything worked perfectly. 
I needed to extend the WiFi so I bought an X95 and followed the wizard to replace the main unit and move the M4 to be connected via wireless backhaul. It all worked but I started experiencing a slow start to streaming video from services like BBC iPlayer and Amazon Prime video or buffering wheels mid-program. My TV is not connected to the M4, it's cabled to the secondary port on one of the M9+'s
I decided to remove all devices, reset and start again from fresh, but I'm still getting the same problem. For some reason, introducing the X95 has really slowed everything down.
I work in IT and have a good understanding of networking but I'm baffled as to what is causing the slow performance. Apart from setting up groups, the only other thing I've done is separate the WiFi channels, but I'm getting this problem even when I'm cabled to an M9+...
Does anyone have any advice of experience of the same thing?
Thanks in advance...
Richard.