Differential Drive not turning the vehicle

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I am using the differential drive controller from the ros2-control package and its gazebo plugin to simulate a 4WD drive differential drive robot. I am basing the measurements of the chassis, tire and their location/joints from the dimensions of a riding mower after converting from imperial to metric of course.

For the chassis I am using a standard box visual geometry for now, and just cylinder geometry for wheels...nothing fancy, you can see the entire URDF here . I studied carefully how to make gazebo valid URDF and was finally able to spawn a working model in gazebo from URDF which is important because the gazebo plugin launches the ros2 controller manager.

Here is the URDF for ros2-control gazebo plugin, and the ros2-control diff-drive controller config. Finally my launch file...

What this all yields is a nice small city world in gazebo (a few streets, road signs, traffic lights and other cars, and my robot model spawned and ready to be controlled via a PS4 controller using the ros2-teleop-joy package, or really just any /cmd_vel Twist message.

The problem is that it is moving forwards and backwards, but not turning, no matter what the angular velocity of the /cmd_vel command is.

I run the following command for example, which should make it move in circles, but instead it just moves forward

ros2 topic pub --rate 30 /tareeqav_base_controller/cmd_vel_unstamped geometry_msgs/msg/Twist "linear:
 x: 0.7
 y: 0.0
 z: 0.0
angular:
 x: 0.0
 y: 0.0
 z: 1.0"

I also tried the standard Gazebo diff drive plugin with the following config

<plugin name="differential_drive_controller" filename="libgazebo_ros_diff_drive.so">


        <!-- wheels -->
      <left_joint>a_fr_left_joint</left_joint>
      <right_joint>b_fr_right_joint</right_joint>

      <!-- kinematics -->
      <wheel_separation>1.25</wheel_separation>
      <wheel_diameter>0.3</wheel_diameter>

      <!-- limits -->
      <max_wheel_torque>20</max_wheel_torque>
      <max_wheel_acceleration>1.0</max_wheel_acceleration>

      <!-- output -->
      <publish_odom>true</publish_odom>
      <publish_odom_tf>true</publish_odom_tf>
      <publish_wheel_tf>true</publish_wheel_tf>


      <odometry_frame>odom</odometry_frame>
      <robot_base_frame>base_footprint</robot_base_frame>
      <command_topic>cmd_vel</command_topic>
 </plugin>

I've played with the controller config min/max velocities, tried changing the wheel radius and distance between wheel. Nothing works beyond driving forwards and backwards.

I've built physical robots where I have 4 wheels and a control signal shared between the two motors on each side and the car drives and turns with no problems.

Any thoughts on what might be happening, or where I should look next?