AI keeps getting stuck in place

i use a simple enemy AI and it keeps getting stuck in place its really annoying can some please help

here is my script:

Code (CSharp):

1.  
2. using UnityEngine;
3. using UnityEngine.AI;
4.  
5. public class EnemyAi : MonoBehaviour
6. {
7.     public bool hasHealth = false;
8.  
9.     public bool attackMode = false;
10.  
11.     public NavMeshAgent agent;
12.  
13.     public Transform player;
14.  
15.     public LayerMask whatIsGround, whatIsPlayer;
16.  
17.     public float health;
18.  
19.     //Patroling
20.     public Vector3 walkPoint;
21.     bool walkPointSet;
22.     public float walkPointRange;
23.  
24.     //Attacking
25.     public float timeBetweenAttacks;
26.     bool alreadyAttacked;
27.  
28.     //States
29.     public float sightRange, attackRange;
30.     public bool playerInSightRange, playerInAttackRange;
31.  
32.     private void Awake()
33.     {
34.         player = GameObject.Find("First Person Player").transform;
35.         agent = GetComponent<NavMeshAgent>();
36.     }
37.  
38.     private void Update()
39.     {
40.         //Check for sight and attack range
41.         playerInSightRange = Physics.CheckSphere(transform.position, sightRange, whatIsPlayer);
42.         playerInAttackRange = Physics.CheckSphere(transform.position, attackRange, whatIsPlayer);
43.  
44.         if (!playerInSightRange && !playerInAttackRange) Patroling();
45.         if (playerInSightRange && !playerInAttackRange) ChasePlayer();
46.         if (playerInAttackRange && playerInSightRange) AttackPlayer();
47.     }
48.  
49.     private void Patroling()
50.     {
51.         if (!walkPointSet) SearchWalkPoint();
52.  
53.         if (walkPointSet)
54.             agent.SetDestination(walkPoint);
55.  
56.         Vector3 distanceToWalkPoint = transform.position - walkPoint;
57.  
58.         //Walkpoint reached
59.         if (distanceToWalkPoint.magnitude < 1f)
60.             walkPointSet = false;
61.     }
62.     private void SearchWalkPoint()
63.     {
64.         //Calculate random point in range
65.         float randomZ = Random.Range(-walkPointRange, walkPointRange);
66.         float randomX = Random.Range(-walkPointRange, walkPointRange);
67.  
68.         walkPoint = new Vector3(transform.position.x + randomX, transform.position.y, transform.position.z + randomZ);
69.  
70.         if (Physics.Raycast(walkPoint, -transform.up, 2f, whatIsGround))
71.             walkPointSet = true;
72.     }
73.  
74.     private void ChasePlayer()
75.     {
76.         agent.SetDestination(player.position);
77.     }
78.  
79.     private void AttackPlayer()
80.     {
81.         if (attackMode)
82.         {
83.             //Make sure enemy doesn't move
84.             agent.SetDestination(transform.position);
85.  
86.             transform.LookAt(player);
87.  
88.             if (!alreadyAttacked)
89.             {
90.                 alreadyAttacked = true;
91.                 Invoke(nameof(ResetAttack), timeBetweenAttacks);
92.             }
93.         }
94.     }
95.     private void ResetAttack()
96.     {
97.         alreadyAttacked = false;
98.     }
99.  
100.     public void TakeDamage(int damage)
101.     {
102.         if (hasHealth)
103.         {
104.             health -= damage;
105.  
106.             if (health <= 0) Invoke(nameof(DestroyEnemy), 0.5f);
107.         }
108.     }
109.     private void DestroyEnemy()
110.     {
111.         Destroy(gameObject);
112.     }
113.  
114.     private void OnDrawGizmosSelected()
115.     {
116.         Gizmos.color = Color.yellow;
117.         Gizmos.DrawWireSphere(transform.position, sightRange);
118.         if (attackMode)
119.         {
120.             Gizmos.color = Color.red;
121.             Gizmos.DrawWireSphere(transform.position, attackRange);
122.         }
123.     }
124. }