When the enemy is hit by the player, it will slide backwards until the end of the world. I’m using Terrain as the ground. Is there anything I need to add, or is there an additional LayerMask setting or something?

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

public class EnemyController : MonoBehaviour
{
    public float lookRadius = 10f;

    Transform target;
    NavMeshAgent agent;
    CharacterCombat combat;

    void Start()
    {
        target = PlayerManager.instance.player.transform;
        agent = GetComponent<NavMeshAgent>();
        combat = GetComponent<CharacterCombat>();
    }

    void Update()
    {
        float distance = Vector3.Distance(target.position, transform.position);

        if (distance <= lookRadius)
        {
            agent.SetDestination(target.position);

            if (distance <= agent.stoppingDistance)
            {
                CharacterStats targetStats = target.GetComponent<CharacterStats>();
                if (targetStats != null)
                {
                    combat.Attack(targetStats);
                }
                FaceTarget();
            }
        }
    }

    void FaceTarget ()
    {
        Vector3 direction = (target.position - transform.position).normalized;
        Quaternion lookRotation = Quaternion.LookRotation(new Vector3(direction.x, 0, direction.z));
        transform.rotation = Quaternion.Slerp(transform.rotation, lookRotation, Time.deltaTime * 5f);
    }

    void OnDrawGizmosSelected()
    {
        Gizmos.color = Color.red;
        Gizmos.DrawSphere(transform.position, lookRadius);
    }
}

Before collide [before collide image] (https://i.sstatic.net/lG4Ukyv9.png)
After collided [after collided image] (https://i.sstatic.net/TMKeLXJj.png)
It will slide until the end of the world [the end of the world] (https://i.sstatic.net/EDSLiIWZ.png)
It’s okay if it still slide, I just need for it not slide too far.