Can i avoid hard edges in terrain?

Before 4033 it was 2017.I have rebuild at 4033 and scale down XY to 50% and that didn’t change anything.Return to scale 100% didn’t change to.
4033 resolution is just increasing size of the map 4.033km 1 pixel = 1m it is not increasing polygon per pixel.
Resampling of the section size to 127x127 quads didn’t help to just eat my ram above 10gb
Maybe it is incorrect shading problem?