Why collision2d happend earlier in rigidboy2d?

I made some test,

This happens if the Rigidbody2D.collisionDetectionMode is in Continious mode change it back to Discrete.

Edit: You can use this code to debug, it will pause the game at collision.

 using UnityEngine;
 using System.Collections;
 
 public class PauseOnTouch : MonoBehaviour {
 
     void OnCollisionEnter(Collision collision)
     {
         Debug.Log(System.String.Format("Recived {1} [OnCollisionEnter] from {0}", collision.collider.name, name));
         Pause();
     }
 
     void OnCollisionEnter2D(Collision2D collision)
     {
         Debug.Log(System.String.Format("Recived {1} [OnCollisionEnter2D] from {0}", collision.collider.name, name));
         Pause();
     }
 
     static void Pause()
     {
         //Debug.DebugBreak();
         Debug.Break();
     }
 }