First you need configure all decos via wifi, one main Deco with cable at router and all other units via wifi. After this. turn off 2nd unit and wire, turn on and "voiala"

 

I got a similar problem with my set of 3 Deco M5 - all three on version 1.4.4 Setup: Main Deco connected to the router via cable. Second Deco is at the edge of the first one's WiFi-signal, but also connected via cable. Everything's fine with that, but it doesn't seem to use the LAN connection (which it should, as it's faster). Third Deco is at the very edge of the WiFi-signal of the second Deco. Everything's fine with the third Deco as long as no cable is plugged in. But as soon as I plug a network cable into it (I've covered the house with cables to make sure I've got a decent signal everywhere) the LED starts blinking red and the Deco App says this Deco "has a problem". WiFi-connection is still up and fast, but the error message persists.

@GajusTempus 

I think I found the reason and solution for this problem: I switched the Deco configuration from Router to Access Point. That solved the issue for me - all wired Decos are now providing the right network and internet.

 

If anyone of the staff should read this: It'd be great if Deco switched to this mode automatically or - at least - recommend it after sensing the network around it.

@GajusTempus 

 

Could you please let me know how can i do this ?

I face the same problem now with one of my Deco ( all 3 Decos are connected via Ether net cable plugged into Router ) 

 

Looking forward to your reply 

 

Thanks

Kiran

@Kiran_Mandarapu 

 

You can switch Deco mesh operating mode in Deco app.