I've loaded a glTF model using the three.js glTF Loader. Although the object is centered on the origin (0, 0, 0), it appears to rotate along the curve of a circle on the x-plane.
This is an image of the model before it begins rotating. Notice that it is on the origin. Here is a GIF on how it rotates after adding mesh.rotation.y += 0.01; to the code.
A visual representation of what I get versus what I'm looking for:
I managed to center the object using this solution, but it doesn't seem to fix the rotation. Bounding box:
    var loader = new THREE.GLTFLoader();
    loader.load( 'model/empire_vase/scene.gltf', function ( gltf ) {
        mesh = gltf.scene;
        gltf.scene.traverse( function ( child ) {
        } );
        var box = new THREE.Box3().setFromObject( mesh );
        box.center( mesh.position ); 
        mesh.position.multiplyScalar( - 1 );
        var pivot = new THREE.Group();
        scene.add( pivot );
        pivot.add( mesh );
        var axesHelper = new THREE.AxesHelper( 100 );
        scene.add( axesHelper );
    } );
Rotation:
function animate() {
    if (mesh) {
        mesh.rotation.y += 0.01;
    }
    requestAnimationFrame( animate );
    renderer.render( scene, camera );
}
The model was pulled from Sketchfab/Geoffrey Marchal but I noticed this issue with other Sketchfab models. Thanks in advance!

