My 600 has issues with the new digital system in Indy. After the last firmware update that fixed the vc/dg issue I noticed that when the audio is garbled and not understandable the control channel flips between vc and dg. If it holds on dg it is crystal clear. Is there a way to make it stay on dg for that system or is it not picking up the signal? It seems to lock onto the cc and holds.