Model : TL-PA4020 KIT(UK)

Hardware Version : 1.0

Firmware Version :

ISP :

Very weird problem perhaps it is my understanding of how the dual port powerline devices work.

I have managed to get one lan port from the sky router into the powerline plug and get the other end synchrosnised and working into a smart tv.

The problem is as soon as I plug an additional lan cable from another port on the sky router into into the powerline plug (the second port) I see the router reset and try to connect to the internet unsuccessfully over and over again. And this happens without me plugging anything on the destination powerline plug.
Have I misunderstood how the 2 ports on these devices work?

The aim is to plug an additional device that requires internet near the TV so I thought I would need to plug 2 separate ports from my router in the 2 ports on the adaptor and then get the output from those 2 ports on the destination adaptor.

All the diagrams on the box only show examples of plugging one port and having one device at the other end hanging off it....even though its a AV500 2 port powerline kit!
It would be nice to see an image or example of how ALL ports can be used and in which way.