write_triangle_mesh with textured OBJ

I'm running a simple I/O test for my textured OBJ mesh file using this code:
```
import open3d as o3d

def visualize(mesh):
vis = o3d.visualization.Visualizer()
vis.create_window()
vis.add_geometry(mesh)
vis.run()
vis.destroy_window()

textured_mesh = o3d.io.read_triangle_mesh("input.obj")
visualize(textured_mesh) # The mesh looks fine here
o3d.io.write_triangle_mesh("output.obj", textured_mesh, write_triangle_uvs=True)
textured_mesh = o3d.io.read_triangle_mesh("output.obj")
visualize(textured_mesh) # The mesh looks broken here
```

The file is read correctly because I can visualize it and it looks just fine.
However, the output obj file is not written correctly. When I visualize it, it looks broken:


The textures are not mapped correctly but also the mesh itself is rasterized in some strange way.