NavMesh Pro doesn´t work perfectly vertically

[Macros-T]

I am using NavMesh Pro for making my enemy follow my player in a 2d game, but my enemy cannot follow my player if its directly above it, in the same x position. At that point my enemy freezes unless I move in the x axis. How can I solve this?

This is my code for the enemy:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AI;

public class scrRobot : scrEnemigoBase
{
    public GameObject ataque1;
    public Transform attackPoint;
    [HideInInspector] public NavMeshAgent agent;
    public GameObject bola;

    public override void Start()
    {
        base.Start();

        cooldown = 100;
        agent = GetComponent<NavMeshAgent>();
        agent.updateRotation = false;
        agent.updateUpAxis = false;
        agent.speed = spd;
    }

    public override void Update()
    {
        base.Update();

        if (agent != null)
        {
            agent.SetDestination(player.transform.position);
        }

        if (cooldown > 0)
        {
            cooldown -= Time.deltaTime;
        } else
        {
            if (canAttack)
            {
                StartCoroutine(Ataque());
            }
        }
    }

    private IEnumerator Ataque()
    {
        agent.speed = 0;
        canAttack = false;
        animator.SetFloat("anim", 1);
        yield return new WaitForSeconds(1.5f);
        Instantiate(bola, attackPoint.position, Quaternion.identity);
        animator.SetFloat("anim", 2);
        canAttack = true;
        cooldown = Random.Range(5, 8);
        agent.speed = spd;
    }
}