[Android Central Question]

Last week a bought Samsung note 9. When I connect my phone to my car's stereo/head unit display (C-Class 2013l) via bluetooth the signal display for cell service displays "No Service" Sometimes it will show a signal for a few seconds when first connected and then will change and show "No Service".
The phone works normal and even i can makes calls. But no service bar shown in my car desplay. I need to restart my phone every time a get in the vehicle so the service bar can show up. Please what is the problem.