Collision Detection Between Instances of Prefabs doesn't work

I have a problem, that may have a simple solution. I'm making a 2D game and I have enemies that spawn and follow a player. Everything works fine, except that when 2 enemies should "repel" each other they just overlap.

I have a script with the AI and I'm manipulating the rigidbodies to move the enemies because I read that it should fix the problem, but it didn't.

Here is the AI code

 using UnityEngine;
 using System.Collections;
 
 public class StFleetAI : MonoBehaviour {
 
     Transform target;
     public float rotationSpeed; 
     Transform myTransform; 
     
     void Start()
     {
         myTransform = transform;
         
     }
     
     void RotateToPlayer()
     {
             float x = target.position.x - myTransform.position.x;
             float y = target.position.y - myTransform.position.y;
             float angle = Mathf.Atan2(x, y) * Mathf.Rad2Deg;
             Quaternion q = Quaternion.Euler(0,0,-angle);
             myTransform.rotation = Quaternion.Slerp(myTransform.rotation,q, rotationSpeed*Time.deltaTime);
     }
     
     void Update () {
         target = GameObject.FindWithTag("Player").transform;
         RotateToPlayer();
         rigidbody2D.AddRelativeForce(new Vector2(0,2500));
         restrictMovement();
         
     }
     
     void restrictMovement()
     {
         if (transform.position.x <= -830) {
             transform.position = new Vector3(-830, transform.position.y, transform.position.z);
         } else if (transform.position.x >= 830) {
             transform.position = new Vector3(830, transform.position.y, transform.position.z);
         }
         
         if (transform.position.y <= -535) {
             transform.position = new Vector3(transform.position.x, -535, transform.position.z);
         } else if (transform.position.y >= 535) {
             transform.position = new Vector3(transform.position.x, 535, transform.position.z);
         }
     }
     
 }

Here is the enemy's setup

I'm not sure if the physics engine works the collisions automatically or if I should use a separate algorithm.

Any help would be awesome, thanks!