We have similar problems in that we get no sound or intermittent sound, error code when first switching on so we have to switch off and on again and also a picture which is constantly breaking up. Similarly we never had these problems with sky and only recently switched to BT for the Champions League for my son - we don't watch anything else on the YouView Box as we use a freesat box on another tv for everything else. We only switched in September, we have tried all the fixes but nothing works. I posted on here last night and a moderator JohnC got in touch. Through him I have forwarded the issue to BT and am awaiting a call. I don't have the time or energy to spend long periods on the phone with them so really want a new box. When you read through the community posts there are lots of similar problems. Hope we both get this issue sorted. Incidentally we can get BT Sport fine on the app on our laptops/phones/tablets.
Yes I will let you know. I agree that it is so frustrating that it takes so long to deal with them on the phone. My model is the T2200