@ca_martin82 

If you plan to run Sky Router, it makes sense to switch Deco mesh to Access Point mode. Otherwise, you are going to have network traffic passing through two routers connected to each other: Sky Router and Main Deco. While this should work in many cases, that network configuration does not make much sense. It is enough to have single router on home network.

With Deco mesh, it is recommended to switch off the WiFi from the Sky Router. You can keep it on, but you will end with two different WiFi networks at your home. Same situation as if you had two independent WiFi routers. Even if you configure them with the same SSID, they will be different WiFi networks: when device decides to roam from Sky Router WiFi to Deco mesh WiFi, that device will briefly lose WiFi connection and experience Internet service interruption.

The point of WiFi mesh, such as Deco, is to ensure device seamless roam between mesh nodes. Add Sky Router WiFi to that mix and not only that capability is lost, but troubleshooting of WiFi problems becomes more challenging.

  @Alexandre. 
 

ok thanks. If I switch to access point mode does this turn the sky router wifi off or do I need to do into the sky admin settings and turn it off?

do you know if performance is effected in access point mode (other than loss of some features) as some articles online seem to state access point mode performance isn't very good. Perhaps I will see what it's like and if no good I will get a new router like the archer AX90. 

  @ca_martin82 

You will have to turn off sky router WiFi through sky admin settings. It won't turn itself off.

In Deco access point mode, you should see performance improvement. Deco can free its CPU from managing network and that may improve it providing WiFi coverage. Sky Router will free its CPU from providing WiFi coverage and will spend all CPU cycles on managing network only.