Feild of view only wokring in specific areas of the scene

Hi all, So I adapted a 3D field of view for an enemy to try and make it 2D, it appeared to all be working fine! Yay, I thought to myself, until it came to moving that enemy around the scene. What once was a perfect working FOV for an enemy completely stopped working and when I moved it to a different location it only partially worked. Tears began to well up and I nearly kicked my computer in it's stupid mocking face as I read though all of the different scripting instructions to make sure that I wasn't doing something stupid. Alas, I couldn't find anything. My gut tells me it has something to do with this line:

"float angle = Vector2.Angle(checkingObject.up, directionBetween);"

but I'm not sure why or how... Any help would be amazing! Ta Code - using System.Collections; using System.Collections.Generic; using UnityEngine;

 public class Fov : MonoBehaviour
 {
     public Transform player;
     public float maxAngle;
     public float maxRadius;
 
     
 
     public bool isInFov;
 
     void Start()
     {
         player = GameObject.FindWithTag("Player").transform;
     }
 
     private void Update()
     {
         isInFov = inFOV(transform, player, maxAngle, maxRadius);
     }
 
     private void OnDrawGizmos()
     {
         Gizmos.color = Color.yellow;
         Gizmos.DrawWireSphere(transform.position, maxRadius);
 
         Vector2 fovLine1 = Quaternion.AngleAxis(maxAngle, transform.up) * transform.forward * maxRadius;
         Vector2 fovLine2 = Quaternion.AngleAxis(-maxAngle, transform.up) * transform.forward * maxRadius;
 
         Gizmos.color = Color.blue;
         Gizmos.DrawRay(transform.position, fovLine1);
         Gizmos.DrawRay(transform.position, fovLine2);
 
         if(!isInFov)
             Gizmos.color = Color.red;
         else
             Gizmos.color = Color.green;
         Gizmos.DrawRay(transform.position, (player.position - transform.position).normalized * maxRadius);
 
         Gizmos.color = Color.black;
         Gizmos.DrawLine(transform.position, transform.forward * maxRadius);
     }
 
     public static bool inFOV(Transform checkingObject, Transform target, float maxAngle, float maxRadius)
     {
         Collider2D[] overlaps = new Collider2D[50];
         int count = Physics2D.OverlapCircleNonAlloc(checkingObject.position, maxRadius, overlaps);
 
         for(int i = 0; i < count + 1; i++)
         {
             if(overlaps[i] != null)
             {
                 if(overlaps[i].transform == target)
                 {
                     Vector2 directionBetween = (target.position - checkingObject.position).normalized;
 
                     float angle = Vector2.Angle(checkingObject.up, directionBetween);
 
                     if(angle <= maxAngle)
                     {
                         RaycastHit2D hit = Physics2D.Raycast(checkingObject.position, target.position, maxRadius);
                         if(hit.transform == target)
                         {
                             return true;
                         }
                     }
                 }
 
             }
         }
 
         return false;
     }
 }