Three js Shadow casting with 3dmLoader

Question

I'm currently working on rendering a 3D model from a 3dmFile using the Rhino 3dmLoader parser in Three.js. I've set up lighting for the scene, including ambient, hemisphere, directional, and point lights, and I'm encountering some unexpected behavior with the directional light and its shadow.

Here's the code snippet for setting up the lighting:

function handleLighting() {
  scene.background = new Color(0xd6dbde);
  scene.add(camera);

  const ambientLight = new AmbientLight(0xffffff, 0.5);
  scene.add(ambientLight);

  const hemisphereLight = new HemisphereLight(0xd6dbde, 0xe2dbcf, 2);
  scene.add(hemisphereLight);

  const directionalLight = new DirectionalLight(0xffffff, 1);
  directionalLight.position.set(1, 1, 1);
  directionalLight.castShadow = true;
  directionalLight.target.updateMatrixWorld();
  scene.add(directionalLight.target);
  scene.add(directionalLight);

  lightHelper = new DirectionalLightHelper(directionalLight, 10);
  scene.add(lightHelper);

  directionalLight.shadow.camera.near = 0.5;
  directionalLight.shadow.camera.far = 500;

  directionalLight.shadow.mapSize.width = 2048;
  directionalLight.shadow.mapSize.height = 2048;

  const pointLight = new PointLight(0xffffff, 1, 100);
  pointLight.position.set(0, 10, 0);
  scene.add(pointLight);
}

However, when I added the light helper, it appeared distorted as shown in this image:

Additionally, before the model is rendered, the shadow appears unusual, as seen here:

I've tried referencing the Three.js documentation and experimenting with a simpler scene setup using basic geometries, which produced the expected results.

Could this issue be related to the camera settings, scene configuration, or something else entirely? Any insights or suggestions on how to troubleshoot and resolve this anomaly would be greatly appreciated.