Array size resets to 0 in inspector.

I have a script that is supposed to spawn a number of GameObjects from an array. The problem occours when i try to set the array size in the inspector. Instead of the size being set, it imidiatly resets to 0.

  public class GamePiece : MonoBehaviour 
     {
         public GameObject[] Blocks;
         public Transform pos;
         public int blockCount;
     
     private float waitTime = 0.5f;
     private GameObject block;
     
     // Use this for initialization
     void Start ()
     {
         Spawn();
     }
     
     // Update is called once per frame
     void Update () 
     {
         
     }
     public void Spawn()
     {
         block = Instantiate(Blocks [Random.Range(0,5)], pos.position, Quaternion.identity) as GameObject;
         Vector3 tmp = pos.position;
         tmp.y = 0;
         tmp.x += 5.11f;
         tmp.z = 0;
         pos.position = tmp;
         StartCoroutine(wait());
     }
     
     IEnumerator wait()
     {
         yield return new WaitForSeconds(waitTime);
         blockCount += 1;
         Spawn();
     }