Dear Bernard,
Thank you for contacting us. I think you need to retune your TV /Box.
You can find the Retuning Guidance on the below link.
visit
www.freeview.co.uk/service-updates for help or follow the instruction below
Press 'Menu' on your remote control (Home on some TVs)
-Find the settings' or 'setup' option
-Select 'first time installation,' 'full retune' or 'default settings'
-if asked for PIN code and you don't know it, try 0000 or 1234
-Your TV or box should start retuning.
I hope I am helpful for your query.
Kind Regards,
Sachin
Broadcast Manager TJC