@animaskie 

Thanks for your patience.

As for the network, is it like this:

Modem—hallway main Deco—switch—LAN—2^nd Deco, wireless to the 3^rd Deco?

----based on the previous network structure, here seemed to be two Deco connected to the Deco together? Is your Deco working on the access point mode?

Would refreshing the APP recover the status of the living room Deco?

Since the signal on the vertical direction is the weakest, maybe a little angle would be much better;

If possible, could you please connect a wired laptop to the living room Deco when it is offline on the APP to check whether there is internet service or not?

Thank you very much and wait for your reply.