@Aidy2020 With M9 Plus and gigabit Internet link, expect WiFi speed on Main Deco to be up to 500-600Mbps if everything is right. M9 Plus is WiFi5. It can't deliver gigabit speeds, so you need to...

@AlexS_in_S Can you clarify how would you want to see them connected? Patio to Lounge or Lounge to Patio?

@Alex_zZ Everything is good with your Deco mesh. I missed one important thing from your description. Satellite Deco connected with Ethernet will not have Connection Preference option. It does not...

@Alex_zZ For this feature to work all Deco units must be on firmware that supports it. To make sure they are, make screenshot of Update Deco page from Deco app and post it here. Example:

@StelvioQ This could be normal if there are walls between Main and Satellite Deco, or they are not in the clear line of sight.

@RingofStone In my experience this usually happens when PC has static IP address configured on it. Deco mesh provides IP addresses in different range than cable router. When PC is connected to cable...