MG MG3 mg3 problem is it says radio module disconnected

Hi I have an appx 6 year old MG3 which I am generally quite happy with except for one thing There is a recurring problem with the radio system with a message “radio module disconnected “ Intriguingly this tends to happen on one particular journey from Didcot,Oxfordshire to the New Forest area I have had two separate local MG dealers(Beaconsfield and Cumnor)look at it under warranty with no apparent problems found though in both instances they did get rid of the error message and returned the radio to proper use…..that is until the next trip to the New Forest area Am I (or the dealers) missing something Hope you can help Colin