@NJRF
When dropping the BT box out of the loop, do not take the aerial cable from the YouView box and plug it in the TV in place of the cable from box to TV (assuming you have that).
Rather, initially, just take both aerial connections from the YouView box and couple them together.
If the problem persists, only then try a cable directly from wall socket to TV. If that is OK, then you are likely looking at the slight, but not negligible, possibility of a problem with the onward cable from box to TV.
You can do this in the opposite sequence if you like, but the important thing is to test both with and without the onward cable, so you don’t erroneously diagnose a problem with the onward cable as a problem with the box.
—————————————————————————————————————
*** Longtime YouView box owner, Broadband customer (was BT, now EE-gulp), finally an EE TV subscriber ***
