Thanks. I have tried the direct cables and I can watch bt sport. Unfortunately I can’t run an aerial and Ethernet to the box simultaneously to check both but I assume this leads us to the solution you suggested.
I am still puzzled as to why it once worked with these plugs but not now. Does that suggest it might be anything else?
As you are a BT YouView customer, I will ask one of the moderators if you qualify for the £20 mini connectors offer, and whether they could arrange for a couple to be sent. That will prove whether its your adapters. Other people have reported issues with some make of adapters.
As @Keith_Beddoe mentioned earlier some powerline plugs have issues with the multicast that bt tv use. The bt mini connectors will solve that problem.
If you read this thread Neilo a forum mod confirms existing bt tv customers can have the mini connectors for £20. He also has a link to follow to request a set.