@nitsuj007 

I have Sony TV 4K (different model than yours), haven't seen anything like that. It is wired to my Main Deco since day 1 of Deco mesh at my house.

I wonder if perhaps your TV Ethernet port failed. You can check that with the help of Satellite Deco: bring it to TV and connect them by Ethernet cable. 

  @Alexandre.  I'll give it a try and follow up. Thanks for the suggestion 

  @Alexandre. 
Yesterday morning I moved a satellite Deco and plugged tv Ethernet in to it.  Light stayed green on routing Deco and everything worked. I then plugged tv Ethernet back into the routing Deco and the light stayed green and internet worked.  Then last night the network stopped working. Deco router light was red. This morning I unplugged the TVs Ethernet cable and the router light immediately turned green and the network is now working.  We use Rokus and Apple TV's for streaming so I'm leaving the Sony OLED offline for now.