rigidbody2d.velocity acting weirdly

I have this bull enemy that I want to charge at (where the player was) until it reaches the border. Then it's supposed to slowly move towards the player (away from the border) to prepare for another attack, but that doesn't happen. I'm using rigidbody2d.velocity to control the bull as it is kinematic. But for some reason even though the direction vectors point towards the player the bull flies off in a weird direction once it reach the map border.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class bull_move : MonoBehaviour
 {
     public Rigidbody2D rb;
     public SpriteRenderer rend;
     public float chargeSpeed;
     public float chargeAcceleration;
     
     public string playerObjectName;
     GameObject player;
     public LayerMask playerLayer;
 
     Vector3 targetPosition;
     Vector3 attackDirection;
     Vector2 attackDirection2D;
     Vector2 playerPosition2D;
 
     bool isFlipped;
 
     public float baseTimer = 1.5f;
     float bullTimer;
     bool readjusting;
     float readjustBaseTimer = 1f;
     float readjustTimer = 1f;
     public float readjustSpeed = 1f;
 
     bool outOfBounds = false;
     
     void Start()
     {
         bullTimer = baseTimer;
         player = GameObject.Find(playerObjectName);
     }
 
     void FixedUpdate()
     {
         if (isFlipped)
         {
             rend.flipX = true;
         }
         else
         {
             rend.flipX = false;
         }
         
         if (!GetComponent<enemyBase>().dead & !readjusting)
         {
             // setting vectors for dashing at previous player location
             if (bullTimer > baseTimer/3)
             {
                 targetPosition = player.transform.position;
                 attackDirection = Vector3.Normalize(targetPosition - this.transform.position);
                 attackDirection2D = new Vector2(attackDirection.x, attackDirection.y);
                 
                 if (targetPosition.x < this.transform.position.x)
                 {
                     isFlipped = true;
                 }
                 else
                 {
                     isFlipped = false;
                 }
             }
 
             // time delay before starting new attack
             bullTimer = TimeDelay(bullTimer);
 
             if (bullTimer <= 0)
             {
                 rb.velocity = (attackDirection2D * Accelerate(chargeSpeed, chargeAcceleration));
             }
         }
 
         // play area border coords
         outOfBounds = !IsBetween(this.transform.position.x, -5.3f, 7.2f) || !IsBetween(this.transform.position.y, -3.5f, 3.5f);
         
         if (outOfBounds & !readjusting)
         {
             StopAttack();
         }
 
         if (readjusting)
         {
             if (readjustTimer > 0)
             {
                 playerPosition2D = new Vector2(player.transform.position.x, player.transform.position.y);
 
                 Debug.Log(playerPosition2D);
 
                 rb.velocity = playerPosition2D;
                 Debug.Log(rb.velocity);
 
                 Debug.Log("readjusting");
 
                 readjustTimer -= Time.deltaTime;
             }
             else
             {
                 bullTimer = baseTimer;
                 readjustTimer = readjustBaseTimer;
                 readjusting = false;
             }
         }
     }
 
     float TimeDelay(float delay)
     {
         float timer = delay;
         if (timer > 0)
         {
             timer -= Time.deltaTime;
         }
 
         return timer;
     }
 
     float Accelerate(float baseValue, float Acc)
     {
         // not working currently
         float momentum = baseValue + (Time.deltaTime * Acc);
         momentum = momentum + (Time.deltaTime * Acc);
         return momentum;
     }
 
     bool IsBetween(float value, float b1, float b2)
     {
         return ((value > b1) & (value < b2));
     }
 
     void StopAttack()
     {
         rb.velocity = new Vector2(0, 0);
         readjusting = true;
     }
 }