@Timbo03 

Hello, 

For a test, please connect a computer to extender PA4010 and make sure computer  can get Internet from the powerline extender first. 

If the computer can get Internet from tp-link unit that means powerline kit is working properly,  you could check more in your network topology: 

May I know your network map, for example :

BT router ----------Sky Q main box  

        \________ main PA4010  .................<powerline> ...... Extender PA4010 ----<Ethernet >--- Sky Q mini box

It is recommended to contact Sky Q box support and send them your current network map and see if they have any suggestion.

Please also check if Sky Q mini box / Sky Q main box is getting an IP address, both should get IP address from  router.