@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 to Main Deco;

and

2. Configure how mobile device connects to Deco nodes and on which WiFi band.

Which one is missing, or is it both not available?

  @Alexandre. 

Hy.

thx for quick respone.

both are not available

my network topology is like this:
- deco network is on router type
- after the main deco i have a gigabit switch where are connected the rest on deco with network cable.

  @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:

  @Alexandre. 

Hy.

Here is my screenshot.

  @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 make sense for Ethernet backhaul.

To test, unplug one of Satellite Deco from Ethernet cable, wait till it established WiFi backhaul and then check if this option appeared for it. 

Device connected by Ethernet to Deco node will not have that option. 

Device connected to Guest Network will not have that option. 

For M9 Plus on firmware 1.6 and with your setup only device wirelessly connected to Deco Main Network will have that option.