Unable to compute fresnel reflections properly

Question

I am implementing fresnel reflections for materials in my renderer.
According to this source, here the look I should obtain when rendering a sphere over a grey background:

I have two implementations. One of them is based on Cook Torrance model.
The implementations use theses helper functions:

float ComputeFresnel0(float ior)
{
    // @See: https://graphicscompendium.com/raytracing/11-fresnel-beer
    return std::powf((ior - 1.0f ) / (ior + 1.0f), 2.0f);
}

float ComputeFresnel(float F0, float NoV)
{
    // @See: https://graphicscompendium.com/raytracing/11-fresnel-beer
    return F0 + (1.0f - F0) * pow(1.0f - NoV, 5.0f);
}

float BlinnPhong(const SampleInput& input, float shininess)
{
    //@See: https://en.wikipedia.org/wiki/Blinn%E2%80%93Phong_reflection_model
    return std::pow(input.HoN, shininess);
}

In term of output, here what i obtain:

NO COOK-TORRANCE, I get this:
IOR = 1

IOR = 4

Source code:

RGBFColor Evaluate_Brdf(const DistributionFunction::SampleInput& distSampleInput, float ior)
{
    // No diffuse. We are only interested in specular.
    RGBFColor diffuse = RGBFColor(0.0f);

    // Specular.
    RGBFColor specular = RGBFColor(1.0f);
    {
        const float F0 = ComputeFresnel0(ior);
        const float F = ComputeFresnel(F0, distSampleInput.NoV);

        static const float shininesss = 256.0f;
        const float specularFactor = F * BlinnPhong(distSampleInput, shininesss);

        specular *= specularFactor;
    }

    return (diffuse + specular) * distSampleInput.NoL; //  Multiply by NoL here for purpose;
}

WITH COOK-TORRANCE, I get this:

IOR = 1

IOR = 4

IOR =4 but no Fresnel

Source code:

RGBFColor Evaluate_Brdf(const DistributionFunction::SampleInput& distSampleInput, float ior)
{
    // No diffuse. We are only interested in specular.
    RGBFColor diffuse = RGBFColor(0.0f);

    // Specular.
    RGBFColor specular = RGBFColor(1.0f);
    {
        const float F0 = ComputeFresnel0(ior);
        const float F = ComputeFresnel(F0, distSampleInput.NoV);

        static const float shininesss = 256.0f;
        float specularFactor = F * BlinnPhong(distSampleInput, shininesss);

        // Cook Torrance.
        specularFactor /= (4.0f * distSampleInput.HoV * distSampleInput.NoL);

        specular *= specularFactor;
    }

    return (diffuse + specular) * distSampleInput.NoL; //  Multiply by NoL here for purpose;
}

As you can see the version with the Cook-Torrance division has the fresnel effect, even without the fresnel term. What I am doing wrong? I outputted the following values to debug:

Thanks for helping!