Finding the shortest path between nodes not working for enemy AI

My code is designed to make the enemy navigate between checkpoints which are manually assigned using the shortest path it can find. It works for the first 2 checkpoints but then gets 'stuck' at the second checkpoint. Can you see what my issue is?

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

 public class enShort3 : MonoBehaviour {
     //this code will find the closest checkpoint to the enemy and move them towards it repeatedly
     
     public GameObject[] verts; //array of checkpoints for enemy to move between
     
     Transform objective; //transform for where enemy is aiming to go
     int shortex = 0; //index for checkpoint with shortest path
     Transform spawn; //ransform for enemies initial spawn
     float shortest = 0; //record of shortest path found
     public float speed = 10f; //speed mutliplier for enemy movement
 
     private void Start()
     {
         spawn = this.transform; //records location at spawn
         shortest = Vector3.Distance(spawn.transform.position, verts[0].transform.position); //default quickest path is between enemy's spawn and first
                                                                                             //checkpoint index
         shortex = 0; //index of first checkpoint
     }
 
     private void FixedUpdate()
     {
         objective = verts[shortex].transform; //enemy's objective is defined by the index of the shortest path found in the array
         this.transform.position += transform.forward * Time.deltaTime * speed; //move the enemy forward constantly
         this.transform.LookAt(objective); //Rotate the enemy towards the objective
 
         if (Vector3.Distance(this.transform.position, objective.position) < 5) //if the enemy is close enough to its current objective...
         {
             for (int x = 0; x < verts.Length; x++) //for every array value...
             {
                 if (x < verts.Length - 3) //if the current index is not 2 below the end of the array... 
                 {
                     if (Vector3.Distance(verts[x].transform.position, verts[x + 1].transform.position) <
                         Vector3.Distance(verts[x].transform.position, verts[x + 2].transform.position)) //check if the distance to the second array index
                                                                                            //is shorter than the distance to the third one as the enemy is
                                                                                            //already at the first index
                     {
                         float temp = Vector3.Distance(verts[x].transform.position, verts[x + 1].transform.position); //record the shorter distance
 
                         if (temp <= shortest) //check if the shorter distance is shorter than the shortest found so far
                         {
                             shortest = temp; //if it is, update the shortest distance
                             shortex = x + 1; //set the index to point towards the shortest distance
                             
                         }
                     }
 
                     else if (Vector3.Distance(verts[x].transform.position, verts[x + 1].transform.position) > //repeat the same here
                             Vector3.Distance(verts[x].transform.position, verts[x + 2].transform.position))
                     {
                         float temp = Vector3.Distance(spawn.transform.position, verts[x + 2].transform.position);
                         if (temp < shortest)
                         {
                             shortest = temp;
                             shortex = x + 2;
                             
                         }
                     }
 
                 }
 
                 objective = verts[shortex].transform; //set the objective using the closest checkpoint found
             }
 
         }
 
     }
 
 }