PBR - Incorrect direct lighting - graphics

Question

Based on many internet resources I wrote PBR implementation for directional lighting for my DirectX 11 game engine, but It works incorrectly.
Bellow, you can see a screenshot where I forced metalness to 0.0f and roughness to 1.0f. As you can see there are too many reflections. For example, the grass is reflective very, but roughness is set to 0, so it shouldn't look like that.
Bellow, I visualized ambientLigting and it looks correct.
Unfortunately, directLighting seems completely off and I don't know why. There are too many reflections. It might be because I applied PBR formulas incorrectly for the directional light source, but I don't know how to make it correct.
Here is my PBR source code. I hope you will help me solve this problem or at least give me a hint, where the problem may be because, to be honest, I have no idea at this moment how to fix it.
static const float PI = 3.14159265359f;
static const float3 DIELECTRIC_FACTOR = float3(0.04f, 0.04f, 0.04f);
static const float EPSILON = 0.00001f;
float DistributionGGX(float3 normal, float3 halfway, float roughness)
{
float alpha = roughness * roughness;
float alphaSquare = alpha * alpha;
float cosHalfway = max(dot(normal, halfway), 0.0f);
float cosHalfwaySquare = cosHalfway * cosHalfway;
float denominator = (cosHalfwaySquare * (alphaSquare - 1.0f)) + 1.0f;
denominator = PI * denominator * denominator;
return alphaSquare / denominator;
}
float GeometrySchlickGGX(float cosinus, float roughness)
{
float r = (roughness + 1.0);
float k = (r * r) / 8.0;
float denominator = cosinus * (1.0 - k) + k;
return cosinus / denominator;
}
float GeometrySmith(float3 normal, float roughness, float cosView, float cosLight)
{
return GeometrySchlickGGX(cosView, roughness) * GeometrySchlickGGX(cosLight, roughness);
}
float3 FresnelSchlick(float cosTheta, float3 F0)
{
return F0 + (1.0f - F0) * pow(1.0f - cosTheta, 5.0f);
}
float3 FresnelSchlickRoughness(float cosTheta, float3 F0, float roughness)
{
return F0 + (max(float(1.0f - roughness).xxx, F0) - F0) * pow(1.0f - cosTheta, 5.0f);
}
int GetTextureMipMapLevels(TextureCube input)
{
int width, heigth, levels;
input.GetDimensions(0, width, heigth, levels);
return levels;
}
float3 Pbr(float3 albedo, float3 normal, float metallic, float roughness, float occlusion,
TextureCube irradianceTexture, TextureCube radianceTexture, Texture2D brdfLut,
SamplerState defaultSampler, SamplerState brdfSampler, float3 lightDirection,
float3 lightColor, float3 cameraPosition, float3 pixelPosition, float shadowMultiplier)
{
lightDirection *= -1;
float3 viewDirection = normalize(cameraPosition - pixelPosition);
float3 halfwayDirection = normalize(viewDirection + lightDirection);
float3 reflectionDirection = reflect(-viewDirection, normal);
float3 F0 = lerp(DIELECTRIC_FACTOR, albedo, metallic);
float cosView = max(dot(normal, viewDirection), 0.0f);
float cosLight = max(dot(normal, lightDirection), 0.0f);
float NDF = DistributionGGX(normal, halfwayDirection, roughness);
float G = GeometrySmith(normal, roughness, cosView, cosLight);
float3 F = FresnelSchlick(max(dot(halfwayDirection, viewDirection), 0.0f), F0);
float3 nominator = NDF * G * F;
float denominator = 4 * cosView * cosLight + EPSILON;
float3 specular = nominator / denominator;
float3 kD = lerp(float3(1.0f, 1.0f, 1.0f) - F, float3(0.0f, 0.0f, 0.0f), metallic);
float3 directLighting = (kD * albedo / PI + specular) * lightColor * cosLight;
F = FresnelSchlickRoughness(cosView, F0, roughness);
kD = lerp(float3(1.0f, 1.0f, 1.0f) - F, float3(0.0f, 0.0f, 0.0f), metallic);
float3 irradiance = irradianceTexture.Sample(defaultSampler, normal).rgb;
float3 diffuse = irradiance * albedo;
int radianceLevels = GetTextureMipMapLevels(radianceTexture);
float3 radiance = radianceTexture.SampleLevel(defaultSampler, reflectionDirection, roughness * radianceLevels).rgb;
float2 brdf = brdfLut.Sample(brdfSampler, float2(cosView, roughness)).xy;
float3 specularColor = radiance * (F0 * brdf.x + brdf.y);
float3 ambientLighting = (kD * diffuse + specularColor) * occlusion;
return ambientLighting + (directLighting * shadowMultiplier);
}