How to Smooth/avoid grainy reflections ?

Hello Everyone,

I am trying to adjust the smoothness of my reflections but I don’t know how can I achieve such goal so I am counting on the great ue4 community.

I know I can improve the sharpness of materials by applying a post process blending material, so I wonder if there is any similar technique to get rid of grains while still retaining the materials sharpness.
I tried to play around screen space reflection intensity quality and max roughness but didnt quite got it right.

without the unsharp blendable material (screen space reflection quality set to 100) the result is grainy reflections

also without post processing there are still grains on the edge of the reflections

with the sharp blendable material the grains get even stronger

in hope we can solve this together,
thank you in advance for the support, cheers!