Graphics DrawMesh/RenderMesh Instanced don't work

In the following code, I try to draw a mesh using 4 different methods:

• DrawMesh and RenderMesh both do work
• DrawMeshInstanced and RenderMeshInstanced both don't work

Code:

private void Update()
{
    // ...

    var count = 0;

    Material.SetPass(0);

    Material.mainTexture = Textures[TextureIndex];

    var rotation = Camera.main!.transform.rotation * Quaternion.AngleAxis(90, Vector3.left);

    foreach (var effect in effects)
    {
        if (effect.count <= 0)
        {
            continue;
        }

        var position = Constants.Transform.MultiplyPoint(effect.pos);

        var matrix = Matrix4x4.TRS(position, rotation, new Vector3(Scale, Scale, Scale));

        Matrices[count++] = matrix;

        if (UseInstanced)
        {
            continue;
        }

        if (UseRenderMesh)
        {
            Graphics.RenderMesh(new RenderParams(Material), Mesh, 0, matrix); // works
        }
        else
        {
            Graphics.DrawMesh(Mesh, matrix, Material, 0); // works
        }
    }

    if (!UseInstanced)
    {
        return;
    }

    if (UseRenderMesh)
    {
        Graphics.RenderMeshInstanced(new RenderParams(Material), Mesh, 0, Matrices, count); // BUG not working
    }
    else
    {
        Graphics.DrawMeshInstanced(Mesh, 0, Material, Matrices, count); // BUG not working
    }
}

The material has enableInstancing set to true as explained in the docs.

There's no warning or error shown in the console but still nothing...

What's wrong?