Gazebo/RViz : Emulated camera can't display STL imported object in RViz

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Hello everyone, I am working on a mobile robot and wanted to simulated it in an environement in Gazebo. When I emulate a camera in gazebo and want to display it in RViz, it only shows certain objects : those that are walls or imported from the gazebo models librarie. All the objects I imported from an stl file with a .sdf (I also tried with types .dae and .obj) do display in gazebo but don't show in the RVIZ display (topic: /3Dcamera/color/image_raw with camera or image displays). Here is the example of the model.sdf that I can display on gazebo but not RViZ: C:\fakepath\model.sdf

Here is the difference in RViz between the box I want displayed and a wheel from a gazebo librarie in front of a wall created with Building Editor in Gazebo: in gazebo:

in RViz:

In the environnement I load, the lines for this particular box is shown below (it's the same principle for every imported stl object):

</model>
<model name='boites_clone_0'>
  <pose>-5.62328 -0.573398 0.4 0 -0 1.3e-05</pose>
  <link name='stl_test_box'>
    <collision name='Wall_4_Collision'>
      <geometry>
        <box>
          <size>0.82 0.85 0.4</size>
        </box>
      </geometry>
      <max_contacts>10</max_contacts>
      <surface>
        <contact>
          <ode/>
        </contact>
        <bounce/>
        <friction>
          <torsional>
            <ode/>
          </torsional>
          <ode/>
        </friction>
      </surface>
    </collision>
    <visual name='Wall_4_Visual'>
      <pose>-0.05 0.1 -0.3 0 -0 0</pose>
      <geometry>
        <mesh>
          <uri>model://world/meshes/bloc-carton.stl</uri>
          <scale>0.001 0.001 0.001</scale>
        </mesh>
      </geometry>
      <material>
        <script>
          <uri>file://media/materials/scripts/gazebo.material</uri>
          <name>Gazebo/DarkYellow</name>
        </script>
      </material>
    </visual>
    <self_collide>0</self_collide>
    <inertial>
      <pose>0 0 0 0 -0 0</pose>
      <inertia>
        <ixx>1</ixx>
        <ixy>0</ixy>
        <ixz>0</ixz>
        <iyy>1</iyy>
        <iyz>0</iyz>
        <izz>1</izz>
      </inertia>
      <mass>1</mass>
    </inertial>
    <enable_wind>0</enable_wind>
    <kinematic>0</kinematic>
  </link>
  <static>1</static>
</model>

I'm using Gazebo 11.9.0 and ROS Noetic on Ubunto 20.04. The STL models come from a mechanical simulation generated inFreeCad. If anyone of you has an ideas or answers to this issue, i'd be pleased to hear them. Thank you.