I have just changed my 2013 Luxury spec is300h for a late 2015 fsport in ultra blue with rose red leather seats both heated and cooled with 3 way drivers memory and premium nav, all was well until the nav screen started returning to the home screen after roughly 15 seconds whenever i select the audio screen, it will stay on the map screen or the energy screen without any problem. I was wondering if i have done something to cause this or is it faulty, has anybody else experienced this. I thought i would ask the question before taking it up with the dealer under Lexus warranty.