I have my Deco connected to my TP switch.TL-SG1016 to the second eithernet port. It does not show up on my on my Deco network either. I do know it is working, as I am using Backhual in my living room...

The way I setup mine is that I have my My Deco conected to my router. in office Deco to 16 port Switch in office Deco attached to switch in living room for backhual. have Roku attached to Deco second...