Why my ball acts if there is a hidden collider?

I am making a ping pong game, it works well, but when the ball hit the border and assumed to disappear and respawned again, after hitting it it doesn't reach the other paddle , but it reflect at fixed point as if there is a collider (See below) and when hitting it again it acts properly, another problem : when the ball hit the borders, a counter is incremented and a message saying if the player won or the AI won, but every time the player counter is incremented the other counter is incremented too, and the only printed message when the AI player win. Here is the code : using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEngine.UI; using System.Text; using System.IO;

 public class PingPongBall : MonoBehaviour {
 
     private float forcex=6f, forcey=15f;
     private Rigidbody2D mybody;
     private int c =0;
     private int c1=0;
     public Text Counter;
     public Text Counter1;
     private Renderer rend;
     public GameObject Ppaddle;
     public GameObject Apaddle;
     int i=0;
 
     void Start() {
         mybody=GetComponent<Rigidbody2D> ();
         Ppaddle = GameObject.Find ("Player_Paddle");
         Apaddle= GameObject.Find ("AI_Paddle");
         Counter.text ="Player1 :" + c.ToString ();
         Counter1.text ="Player2 :" + c1.ToString ();
         rend =this.GetComponent<Renderer>();
         rend.enabled = true;
     }
 
 
 
     IEnumerator pause ()
     {
         mybody.velocity = new Vector2 (0f, 0f);
         yield return new WaitForSeconds (1.5f);
         rend.enabled = true;
         mybody.velocity = new Vector2 (10f  , -14f );
 
     }
 
 
 
     void WinnerCheck() {
         if (i==5){
         if (c1 > c) {
             print ("You win!");
         }
 
         if (c > c1) {
             print ("You loose!");
 
         }
     }
     }
 
 
     void OnCollisionEnter2D (Collision2D col)
     {
         if (col.gameObject.name == "Player_Paddle") {
             
             
             if (Input.acceleration.x > 0f) {
                 mybody.velocity = new Vector2 (10f, 14.5f);
 
             } else if (Input.acceleration.x < 0f) {
                 mybody.velocity = new Vector2 (-10f, 14.5f);
 
             } else {
                 mybody.velocity = new Vector2 (0, -14.5f);
 
             }
         }
 
         if (col.gameObject.tag == "AI_Paddle") {
             mybody.velocity = new Vector2 (forcex, -forcey);
         }
 
         if (col.gameObject.tag == "Top") {
             i++;
             if (c1 <= 4) {
                 c1++;
                 Counter1.text = "Player2 :" + c1.ToString ();
                 rend.enabled = false;
                 transform.position = new Vector3 (3.5f, 1f, 0);
                 StartCoroutine (pause ());
             } else {
                 WinnerCheck ();
                 gameObject.SetActive (false);
                 Time.timeScale = 0;
             }
         }
 
 
         if (col.gameObject.tag == "Ground") {
             i++;
             if (c <= 5) {
                 c++;
                 Counter.text = "Player1 :" + c.ToString ();
                 rend.enabled = false;
                 transform.position= new Vector3 (3.5f, 1f, 0);
                 StartCoroutine(pause());
 
             } else { 
                 
                 WinnerCheck ();
                 gameObject.SetActive (false);
 
                 Time.timeScale=0;
             }
     }
 }
 }