Operator error. The voice disappearing is a known problem when you remove the thumb drive before the update is finished. Unfortunately, there are a couple restarts during the update that can give the impression that it's finished. You need to find a time when you have 2 solid hours for the truck to update, and wait until you see the last message announcing the software update is done and you can remove the USB, which will probably take almost the whole 2 hours. The update will not restart from where it left off, you have to do the whole thing over.