Threebox GLTF Model partly wrong

Question

I have an fbx model that i exportet as an embedded gltf in blender. When i load it into a map with threebox then it looks wrong but in the gltf viewer of threejs it looks right. What am i doing wrong?

Some parts seem to work but some are completely white or partly transparent which is not in the original model and not in the GLTFViewer.

The code is pretty straightforward:

const pokemonOptions = { obj: 'models/pokemon/beedrill/model.gltf', type: 'gltf', scale: 2, units: 'meters', rotation: { x: 0, y: 0, z: 0 } };

this.tb.loadObj(pokemonOptions, (model) => {
     model.setCoords([this.player.lng, this.player.lat]);
     this.tb.add(model);
});

And i also tried loading it with threejs manually but it still looks wrong.