@Con-Hennekens It was moving off the Android Auto screen but may have also been doing it on the Phone but I was unable to check while I was driving (and I was driving my wife nuts asking her to keep checking the status on the phone and AA car display!)
@Nick-Carthew thanks Nick, it's a strange one as there is no lag on Google maps, TTGo or Sygic. I'll keep messing around with the settings to try to solve it as the integrated native of the app with the excellent planner appeals to me.