Fractal noise area creating strange artifact lines

Question

I have a relief created from Perlin's Fractal Noise diagram that generates a pretty wonderful landscape. The problem I am facing is a few invisible lines running along both the X and Z coordinates, I think this is due to fractal generation, but since I created a two-dimensional picture, I do not see any artifacts. Artifact lines

The landscape is generated by dividing the area into pieces, which, in turn, are divided into tiles, which, depending on the resolution, have a size.

With each tile, I calculate the four corners in the same way for each corner part:

float corner1 = mapHeight * fractal( x * tileSize +( posX * (mapSize) ) , z * tileSize +( posZ * (mapSize)) ,25000,0.5,16);

Fractal function:

float fractal(int x,int y,float gridSubs,float gain,int octaves){
  float total = 0;
  float freq = 1.0/gridSubs;
  float amp = gain;

  for(int f=0;f<octaves;f++){
    total += noise(x*freq,y*freq)*amp;
    freq *= 2.0;
    amp *= gain;
  }
  return total;
}

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Answer 1

, , , noiseDetail?

http://www.processing.org/reference/noiseDetail_.html

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Answer 2

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