@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...

@Alex_zZ I have Deco mesh with M9 Plus and I see Connection Preference in Deco app. Connection Preference feature is actually two features: 1. Configure how Satellite Deco connect to each other and...

@Hispanico You are saying that you have 6 identical EchoDot (Alexa) devices, but on screenshots one is connected to 5GHz band, another - to 2.4GHz band. There is a difference. Is it possible that one...