GLTF model only showing in Inspector "Show Frustums"

Hi, any thoughts on why GLTF model (cesium milk truck) only showing in Inspector “Show Frustums” ?
When “Show Frustums” is turned OFF, it is not shown at all.

Cesium (CesiumJS v1.74) is used through another library, so not sure what’s going on, some pointers will be great

Code

      const heading = Cesium.Math.toRadians(0);      
      const pitch = Cesium.Math.toRadians(0);
      const roll = Cesium.Math.toRadians(0);
      const hpr = new Cesium.HeadingPitchRoll(heading, pitch, roll);
      const position = Cesium.Cartesian3.fromDegrees(
        pose.geometry.coordinates[0][0],
        pose.geometry.coordinates[0][1],
        20
      );
      const orientation = Cesium.Transforms.headingPitchRollQuaternion(position, hpr);
      const entity = {
        name: `${pose.properties.assetId}`,
        position,
        orientation,
        model: {
          uri: "CesiumMilkTruck.glb",
          minimumPixelSize: 50,
          heightReference: window.Cesium.HeightReference.RELATIVE_TO_GROUND,
          show: true,
          ready: true,
          scene: window.viewer.scene,
          scale: 1,
          debugShowBoundingVolume: true
        }
      };

Solved, the model is now displayed once I turned on Shadow through the 3rd party library