My understanding of the situation is the following:

1. The car must connect to home via cellular to authenticate/receive updates over some regular cadence (days? hours?) 2. Once that is complete, the user can authenticate over phone to the service via any connection (ie airbnb wifi), then unlock the car with bluetooth 3. The situation here occurred after going beyond cell service range for the car. It tried to connect home, failed, and as a result, refused to honor the phone's unlock the car itself had connected to home over cellular