Why my mesh is flat and change position?

Question

Befor Start: (It's basic cube)

After Start: (It's must be Eye)

Code:

IngredientAsset:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

[CreateAssetMenu(fileName = "New Ingredient", menuName = "Ingredient")]
public class IngredientAsset : ScriptableObject {

    public Mesh ingredientMesh;

}

Ingredient:

using System.Collections.Generic;
using UnityEngine;

[System.Serializable]
public class Ingredient : MonoBehaviour {

    public IngredientAsset asset;



    public Ingredient (IngredientAsset a) {
        asset = a;
    }

    public bool HasIngrediend()
    {
        if (asset == null) {
            return false;
        } else {
            return true;
        }
    }

    public Mesh GetIngrediendMesh()
    {
        if (asset == null) {
            return null;
        }

        return asset.ingredientMesh;

    }


}

TableBox:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class TableBox : MonoBehaviour {

    public MeshFilter overlay;

    public IngredientAsset ingredient;
    public EquipmentAsset equipment;

    private void Start()
    {
        if (ingredient!=null) {
            overlay.mesh = ingredient.ingredientMesh;
        } else if (equipment != null) {
            overlay.mesh = equipment.equipmentMesh;
        }
    }

    public void Interact(IngredientAsset c, EquipmentAsset t, PlayerInteraction player)
    {
        player.SetIngredient(ingredient);
        ingredient = c;
        player.SetEquipment(equipment);
        equipment = t;

        if (equipment != null)
            overlay.mesh = equipment.equipmentMesh;
        else if (ingredient != null)
            overlay.mesh = ingredient.ingredientMesh;
        else
            overlay.mesh = null;
    }
}

PlayerInteraction:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerInteraction : MonoBehaviour {

    public GameObject target;

    public KeyCode interactKey;


    [SerializeField]
    private IngredientAsset ingredient;
    [SerializeField]
    private EquipmentAsset equipment;

    private void Update()
    {
        if (Input.GetKeyDown(interactKey))
        {
            if (target == null)
                return;

            TableBox table = target.GetComponent<TableBox>();
            if (table != null)
            {
                table.Interact(ingredient, equipment, this);
            }

        }
    }

    public void SetIngredient(IngredientAsset c)
    {
        ingredient = c;

    }


    public void SetEquipment(EquipmentAsset t)
    {
        equipment = t;

    }


    private void OnTriggerEnter(Collider col)
    {
        if (target != col.gameObject && target != null)
        {
            Deselect();
        }

        target = col.gameObject;

        }
    }

    private void OnTriggerExit(Collider col)
    {
        if (col.gameObject == target)
        {
            Deselect();
            target = null;
        }
    }

    void Deselect()
    {

    }
}

My project.

P.S. What if I wanna change my code to work with prefabs, what I must to do? Or What I must to do that my mesh looks like my prefabs?

Thanks for attention!