Adjust the blurrness in HDRI scene

Questions
1

Hi,

I imported the HDRI scene into the scene (4K resolution), there lot of blurness in the scene
tried by adjusting the below ones but no luck.

 const environmentMap = new BABYLON.HDRCubeTexture(environmentURL, scene, 256, false, true, false, true)
environmentMap.updateSamplingMode(BABYLON.Texture.TRILINEAR_SAMPLINGMODE);

Irrespective of the .hdr file resolution we are not able to adjust the blurrness,
can somebody share some ideas to fix this

Thanks
vij