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I have moved your post to a new thread, so you can get help from the community.
Its possible your TP Link router does not support multicast.
Which one is it?
There have been a number of posts regarding this router. As this is not an issue with the YouView Box or service, I am moving this post to the general broadband board, where discussions about routers normally take place.
If you search that board or all the boards, you may find those posts.
From the left hand menu select IPTV > tick enable IPTV, select LAN port that you are using for You view box, select VDSL, tick VLAN enable, enter 101 or that doesn't work try 102. Click save.