Just bought a new Smart TV and am trying to connect it to both router and BT box. Currently have aerial lead going to TV, Ethernet from hub to box and HDMI linking box and TV. Can get all the TV channels and internet apps, but can’t locate my BT subscription channels. Whenever I change the AV setting to the relevant HDMI port it just says ‘signal not strong enough’ or words to that effect. Suspect my cable configuration is wrong, but can anyone advise?