Landscape Blocky like minecraft after Importing Heightmap

Hi,

when I import a heightmap for landscape I get a terrible looking terrain with blocky layers like minecraft.
I have all the settings as per epic’s recommendations.

I have tried loads of different heightmaps with the same result, also upped the section size and resampled this just made it look like smoother blocky layers. I have attached a screen shot, thanks in advance for any assistance.