I'm looking at my Pixel 3 and its navigation settings have the toggles for "Play voice over Bluetooth", "Play voice during phone calls" and "play audio cues". There's also a Play test sound item (actually a button). What happens if you tap that while outside your car, inside your car and once your car's turned on?
What if you turn off Play voice over Bluetooth? Also, again, what if you turn off Bluetooth on your phone?
There are also probably other nav apps for Android besides Google Maps and Waze.
'19 Bolt Premier
'13 Leaf SV w/premium (owned)
'13 Leaf SV w/QC + LED & premium (lease over)
Please don't PM me with Leaf questions. Just post in the topic that seems most appropriate.