Yesterday I started a journey but had to loop back to get fuel. Navigator (Android on Android auto) just showed the rotating "whirlygig". Even after stopping and restarting the car it didn't recover and I had to exit the route and ask it to calculate again.
It's has done this for years (many versions) but doesn't happen every time. It seems to be if you depart from the navigated route such as for stops on long journeys or to get fuel locally before proceeding.