@Ravish Where is the main Deco? 

Does the satellite Deco have a strong backhaul connection with the main Deco?

Do you have a strong wifi connection between a device from the first floor to the Deco in the ground floor?

Is "fast roaming" enabled for your Deco mesh?

  @yves_b  Yes I do have good wifi between deco. I tested with cable backhaul too. 

I tested with fast roaming ON and OFF, both scenarios. 

  @Ravish 

It is, ultimately, the decision of the device, to remain connected to a Deco or to connect to another Deco.

The Deco mesh does two things:

- inform the device about when it is appropriate to change (if the device supports that protocol)

- help the device minimising the impact of that change, making it transparent

Are you sure the device actually remains connected to the original Deco?  The app does not always show the correct state.

Under Windows, "netsh wlan show interfaces" shows the BSSID of the wifi network, which is the MAC address of the Deco (visible in the app in the details of the Deco).

Under Windows, some wifi interfaces allow configuring the roaming aggressiveness, you might want to adjust that to an higher value.

  @yves_b  When I saw there is network issue, then I check the deco app. When ever there is a connectivity issue I can see that the device is connected to wrong(far) deco, so using app I switch to correct one.  

I used to hear that "some device may have issue". But here I am taking aboute latest IPhone and Macbook. Deco is not compatable with Macbook and iphone ?

Do we need a specific configuration for macbook and iphone?

  @Ravish You did not initially describe that you had network issues.  Do you mean that your devices do not have a good connectiviy with Internet?

  @yves_b I dont mind the device is connected to far or near router. If the device is connecting to a far router wifi signal will be week and network speed slow dowm.

I was expecting the mesh network will switch wifi in atleast in a worst scenario. In this photo you can see it is not switching. 

  @Ryan That means deco is not useful for Iphone and Macbooks. I will write the review accordingly so that who ever planning to buy they can go for normal router instead of Deco Mesh. So that at least they can switch the router manually from the phone or laptop.

  @Ravish 

I read, in the information provided by Apple, that the Deco mesh is useful for Apple devices:

• The roam scan runs more quickly if 802.11k is enabled on the network.
• 802.11r streamlines the authentication process when your device roams from one AP to another on the same network.
• When a device must roam, the BSS transition data (supplied by the network via 802.11v) is reviewed so the device can quickly determine which access points are best for roaming

I understand you do not concur with Apple approach (not switching until the existing wifi connection becomes too weak).