OnTriggerStay() not working

For some reason that I've spent a full hour trying to explain, when I try to check if a civilian enters a zombie trigger, nothing happens. I even set up a debug.log which does absolutely nothing. Is there some massive glaring issue that I don't see?

Civilian Script:

 public class CivlianScript : MonoBehaviour
 {
 
   public Transform end;
   private Vector3 end2;
   private NavMeshAgent agent;
   private GameObject Civilian;
   private float timetime;
   public float MaxHealth;
   private float Health;
   // 1 == Zombie, 2 == Bullet, 3 == Cop Misfire
   private int WhatDealtLastDamage;
   public GameObject Zombie;
 // shit
     void Start() {
       agent = GetComponent<NavMeshAgent>();
       end2 = new Vector3(end.position.x, end.position.y, end.position.z);
       Civilian = GetComponent<GameObject>();
       agent.SetDestination(end2);
       timetime = Time.time + 2;
       Health = MaxHealth;
     }
 
     void OnTriggerStay(Collider other) {
       if (other.gameObject.CompareTag("Zombie")) {
         WhatDealtLastDamage = 1;
         Debug.Log(other.gameObject.GetComponent<ZombieScript>().Damage);
         Health -= other.gameObject.GetComponent<ZombieScript>().Damage;
       }
     }
 
     // Update is called once per frame
     void Update()
     {
       Debug.Log(Health);
       if (timetime < Time.time) {
         if (agent.remainingDistance < 10) {
           Destroy(gameObject);
         }
       }
 
       if (Health < 1) {
         if(WhatDealtLastDamage == 1) {
           Instantiate(Zombie, this.transform.position, this.transform.rotation);
           Destroy(gameObject);
         }
       }
     }
 
 
 }
 

Zombie Script:

 public class ZombieScript : MonoBehaviour
 {
 
     public UnityEngine.AI.NavMeshAgent zombie;
 
     private Vector3 EnemyPosition;
 
     public LayerMask humanMask;
 
     private GameObject[] enemies;
 
     private List<Transform> enemytransforms = new List<Transform>();
 
     private Transform ClosestEnemy;
 
     private int I;
 
     public float MaxHealth;
 
     private float Health;
 
     public float Damage;
 
     void Awake() {
 
     }
 
     // Start is called before the first frame update
     void Start() {
       zombie = GetComponent<NavMeshAgent>();
       LayerMask humanMask = LayerMask.GetMask("Human");
       }
 
     // Update is called once per frame
     void Update()
     {
       I = 0;
       enemytransforms.Clear();
       enemies = GameObject.FindGameObjectsWithTag("Human");
       foreach (GameObject enemy in enemies) {
         enemytransforms.Insert(I, enemy.transform);
         I++;
       }
       ClosestEnemy = GetClosestEnemy (enemytransforms, this.transform);
       zombie.SetDestination(new Vector3(ClosestEnemy.position.x, ClosestEnemy.position.y, ClosestEnemy.position.z));
     }
 
     Transform GetClosestEnemy (List<Transform> enemy, Transform fromThis) {
       Transform bestTarget = null;
       float closestDistanceSqr = Mathf.Infinity;
       Vector3 currentPosition = fromThis.position;
       foreach(Transform potentialTarget in enemy) {
         if (potentialTarget != null) {
           Vector3 directionToTarget = potentialTarget.position - currentPosition;
           float dSqrToTarget = directionToTarget.sqrMagnitude;
           if (dSqrToTarget < closestDistanceSqr) {
             closestDistanceSqr = dSqrToTarget;
             bestTarget = potentialTarget;
           }
         }
         }
       return bestTarget;
     }
 
     void OnTriggerStay(Collider other) {
       if (other.gameObject.CompareTag("Bullet")) {
 
       }
      }
 }