i used google maps/navigation once and it worked fine with voice prompts. Now when i use it, i get the correct map navigation but no voice prompts. here is my checklist: 1 - i keep my phone on vibrate, would that be stopping it? 2 - the pico TTS is installed and is working when i do a sound check 3 - i checked if it was muted, it is unmuted. what could have caused it to stop working and what can/should i do to get it back working? I really like the feature.