Problem with killing enemies with fire script

Problem:
Hey guys,
I have a problem, I wrote a script that damages player each second when he enters some flame.
Then I wanted to apply it to enemies, so I gave them tag “Enemy”, and wrote the same for them.
For player it works perfectly, but for enemies it just damage one of them and even when he is killed, others are not damaged then, it looks like it applies on just one of them, but they are totally identical/duplicated, so I don’t understand why, when every of them has their own hp etc.

Code:
using System.Collections;

public class ohen:MonoBehaviour{
PlayerHealth playerHP;
EnemyHealth enemyHP;
GameObject player;
GameObject enemy;
BoxCollider trigger;

bool EnemyIsInFire;
bool PlayerIsInFire;
public float timeBetweenDamages=0.5f;
float timer;
public int dmg=5;

//Use this for initialization
void Awake(){
player=GameObject.FindGameObjectWithTag(“Player”);
enemy=GameObject.FindGameObjectWithTag(“Enemy”);
enemyHP=enemy.GetComponent();
playerHP=player.GetComponent();

}

//Update is called once per frame
void Update(){
timer+=Time.deltaTime;
if(timer>=timeBetweenDamages&&PlayerIsInFire){
AttackPlayer();
}

if(timer>=timeBetweenDamages&&EnemyIsInFire){
AttackEnemy();
}

}

void OnTriggerEnter(Collide rother){
if(other.gameObject==player){
PlayerIsInFire=true;
}
if(other.gameObject==enemy){
EnemyIsInFire=true;
}

}

void OnTriggerExit(Collider other){
if(other.gameObject==player){
PlayerIsInFire=false;
}
if(other.gameObject==enemy){
EnemyIsInFire=false;
}
}

void AttackPlayer(){
timer=0f;
if(playerHP.currentHealth>0){
playerHP.TakeDamage(dmg);
}
}

void AttackEnemy(){
timer=0f;
enemyHP.TakeDamageByFire(dmg);

}

}

Could you show us some screenshots of the enemy game objects?

You need to use FindGameObjectsWithTag (with an S - plural), and then you need to loop through the resulting array of all enemy gameObjects.