Welcome to this user forum.
Try changing the video output resolution of the BT YouView box. Try 1080i.
Thanks, I never thought I'd need to change the resolution. I take it this is an ongoing problem since you knew exactly what it was I needed to do.
So my question is, how are BT going to fix it? I never needed to change the resolution on my older LG FHD TV.
Its not an issue with the BT YouView box, its simply that the resolution you were using, is not supported by your TV.
What did you have it set to originally, and has changing it to interlaced sorted the problem?
I assume you had it set to 1080p (progressive)?