I don't really know much about services outside of the US, however from looking at the way that some SkyQ boxes are set up, they may be already communicating with each other over a powerline connection instead of your network. If your boxes support an ethernet connection, I would imagine that this would stop the device from trying to communicate via Powerline.

Can you confirm that the SkyQ box is not relying on a powerline connection to receive a signal?

  @Vic83,

If it's connected via WPS, that means it is just a simple Wi-Fi connection, the WPS is just the setup method. 

If you aren't positive, try to place your SkyQ boxes on surge protectors, as this would prevent the Powerline data from flowing. It sounds as though the device may be configured to work via Wi-Fi but switch to a powerline when it is detected. If you have other SkyQ boxes, these devices may also be trying to make use of a powerline connection. 

Have you tried to restart the SkyQ Box after you have activated your TP-Link powerline network?

I would recommend posting to the global forums, as a user may have a solution for your SkyQ box already. The United States doesn't have SkyQ as a provider, and to further add, Powerline connections are far more popular outside of the US than inside. You will probably have better luck finding possible solutions there.