Welcome to our Community and thanks so much for your first post - as our VIP @Graham_A advised, you most likely do not subscribe to the HD version of these channels. For Sky Sports, there is a £7 a month fee to watch Sky Sports HD channels
Sky Sports News HD and Sly Sports Mix HD are available on our Full house and Maxit package as standard and Sly Sports Racing HD is available on all packages as standard
You can check your account online to see what package you subscribe to. If you do not subscribe to the HD channels, you can upgrade via your TV or your online account.