My understanding that the Android Auto available to be enabled under “System Settings > Apps > Preinstalled Apps” can be considered a “shim” or “stub” in itself. It essentially sets up the namespace, etc., at the system level required by AA, but is not by itself a functional Android Auto implementation. Instead, after you enable it, then you will need to “update” Android Auto from Aurora (effectively installing the “real” Android Auto).
Some basic “from square 1” guidance is here in our documentation: Android Auto - iodé