RVIZ2 not displaying visuals

edit

I just started learning ROS2 by porting the osrf prius simulation to ROS2 and here i ran into the problem that rviz2 is not displaying the visuals (as seen in the figure)

However when I change the Description Source to File the visuales are displayed (see below)

Any idea how to solve this?

Edit: I am loading the urdf as follows:

       urdf = os.path.join(
           get_package_share_directory("prius_description"),
           "urdf", urdf_file_name)

       Node(
           package="robot_state_publisher",
           executable="robot_state_publisher",
           name="robot_state_publisher",
           namespace="prius",
           output="screen",
           parameters=[{"use_sim_time": use_sim_time, "robot_description": robot_desc}],
           arguments=[urdf]
        ),