Hi, Keep getting a message “no or weak signal” only on ITV channel (ITV, ITV 2 etc). Purchased a signal booster but made no difference. Perfect picture if I use the aerial just on the tv. After re-scan ITV comes back but jumpy then disappears again. All cables are good, aerial is reasonably short and connector is not loose. Loft aerial and only connected to one TV. Anyone have any ideas what is happening?