Terrain Stitching

Hello,
I'm relatively new to procedural terrain generation, but right now I am trying to create a procedurally-generated world using multiple terrains, by using SetHeights to map an array of floats onto the terrains. However, the terrains don't connect at the seams even though I tried to write a stitching algorithm (below). I would really appreciate some help as to what I'm doing wrong here. Thanks!

 void SetNoiseTexture(float[,] noise)
 {
     Terrain[,] terrains = new Terrain[width, height];

     for (int x = 0; x < width; x++)
     {
         for (int y = 0; y < height; y++)
         {
             var chunk = GetChunk(noise, x * _resolution, y * _resolution, _resolution);
             if (x > 0)
             {
                 StitchLeft(chunk, GetChunk(noise, (x - 1) * _resolution, y * _resolution, _resolution), _resolution);
             }
             if (y > 0)
             {
                 StitchBottom(chunk, GetChunk(noise, x * _resolution, (y - 1) * _resolution, _resolution), _resolution);
             }

             var t = Instantiate(terrain).GetComponent<Terrain>();
             terrains[x, y] = t;

             t.terrainData = Instantiate(t.terrainData);
             t.gameObject.GetComponent<TerrainCollider>().terrainData = t.terrainData;

             t.transform.position = new Vector3((x - width/2) * t.terrainData.size.x, 0, (y - height/2) * t.terrainData.size.z);
             t.terrainData.SetHeights(0, 0, chunk);
         }
     }
 }

 float[,] GetChunk(float[,] array, int x, int y, int length)
 {
     float[,] ret = new float[length, length];

     for (int i = 0; i < length; i++)
     {
         for (int j = 0; j < length; j++)
         {
             ret[i, j] = array[i + x, j + y];
         }
     }

     return ret;
 }

 void StitchLeft(float[,] chunk, float[,] neighbor, int resolution)
 {
     for (int i = 0; i < resolution; i++)
     {
         chunk[0, i] = neighbor[resolution - 1, i];
     }
 }

 void StitchBottom(float[,] chunk, float[,] neighbor, int resolution)
 {
     for (int i = 0; i < resolution; i++)
     {
         chunk[i, 0] = neighbor[i, resolution - 1];
     }
 }