Tilemap Collider Script

TilemapScript.cs

public class TilemapScript : MonoBehaviour
{
    Tilemap tilemap;
    Tile tileGreen;
    Tile tileBlack;
    TileBase tileCheck;

    private void Awake()
    {
        tileGreen = Resources.Load<Tile>("Green") as Tile;
        tileBlack = Resources.Load<Tile>("Black") as Tile;
    }

    // Start is called before the first frame update
    void Start()
    {
        tilemap = GetComponent<Tilemap>();
    }
    // CHANGE TILES ACCORDING TO COLLISIONS
    void OnCollisionEnter2D(Collision2D collision)
    {
        Vector3 hitPosition = Vector3.zero;
        {
            if (tilemap != null && Manager.Instance.go_Radar == collision.gameObject)
            {
                foreach (ContactPoint2D hit in collision.contacts)
                {
                    hitPosition.x = hit.point.x;
                    hitPosition.y = hit.point.y;
                    hitPosition.z = 0;
                    tileCheck = tilemap.GetTile(tilemap.WorldToCell(hitPosition));
                    if (tileCheck == tileBlack && tileCheck != null)
                    {
                        tilemap.SetTile(tilemap.WorldToCell(hitPosition), tileGreen); // PROBLEM: IT ONLY TURNS GREEN THE FIRST TILES IT COMES IN CONTACT WITH.
                    }
                }
            }
        }
    }
}