My 3D preview is not displayed

Hello

I've upload my own 3D object. You can see in my screenshot : my object and my material are named "custom".

Here my json :

{

 "id": "insulated",

 "name": "Insulated",

 "print_area": {

  "width": 225,

  "height": 210

 },

 "camera_z": 25,

    "base_material_metalness": 1,

    "base_material_roughness": 0.1

}

But in my product personnalisation page there is no 3D preview. If I set your 3D can the preview is displayed.

What not mine ? Thanks