Why is StaticBatchingUtility not completely combining all of my meshes?

I'm trying to create a 3d procedural voxel terrain generator.. I've seen things on how batching will allow for optimization. I've tried the SetActive(); fix that a couple people have suggested, it does not work. Although it does batch, it separates them in to four parts instead of one static mesh. Everything is static, It's in a empty game object called terrain_container. I've tried disabling shadows, lighting, etc.. and I've heard that shaders might be breaking the batching, but I haven't put in any of my own shaders.

This is what it looks like, the combined mesh. As you can see there are 4 separate meshes.. Why?

This is what I'm trying to batch. And my code;

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class GenerateTerrain : MonoBehaviour {
     
     public static GameObject vox_blank = Resources.Load("Voxels/vox_blank") as GameObject;
     public static List<GameObject> Blocks = new List<GameObject>();
     public static int Voxels;
     public static GameObject[] vv;
 
 
     public static void Generate(int size_x, int size_y, int size_z){
         float voxelScale = vox_blank.transform.localScale.x;
         Voxels = 0;
 
         vv = new GameObject[size_x * size_y * size_z];
 
         GameObject terrain_container = new GameObject();
         if (GameObject.Find ("Terrain"))
             Destroy (GameObject.Find ("Terrain"));
 
         terrain_container.name = "Terrain";
         terrain_container.isStatic = true;
         terrain_container.tag = "blankVoxel";
 
         for (float x = 0; x < size_x; x += 1) {
             for (float y = 0; y < size_y; y += 1) {
                 for (float z = 0; z < size_z; z += 1) {
                     GameObject newVoxel = GameObject.Instantiate (vox_blank);
                     newVoxel.transform.SetParent (terrain_container.transform);
                     newVoxel.transform.position = new Vector3 (x, y, z);
                     newVoxel.name = "vox_blank";
                     newVoxel.tag = "blankVoxel";
 
                     vv [Voxels] = newVoxel;
                     Voxels++;
                 }
             }
         }
 
 
 
         print (vv.Length + " voxels");
         print ("Done terrain");
 
 
         foreach (GameObject obj in vv) {
             obj.SetActive (false);
             obj.SetActive (true);
         }
 
         StaticBatchingUtility.Combine (vv, terrain_container);
 
 
         //StaticBatchingUtility.Combine (Blocks.get);
     }
 }