DAB issue

[Norfolkram]

Hi all,i have an 11 plate 3.0 d xf which has an annoying glitch.Mostly on cold mornings the DAB radio goes searching but never finds any channels, if i switch the engine off for 5 minutes or so when I restart the engine all the channels reappear and all is well for the rest of the day, next morning if cold same again if the weather is mild it will work ok ,any ideas would be appreciated.