My health potion worked and now it doesn't.

I have a health potion in my 2d game that is supposed to give 2 hp back. At first it did. But then I added some map elements and now it only gives 1hp back. The code hasn't changed. I don't know what is going on.

I don't know if this is the right way to go about making a health potion but I am really new and this is the only thing I could think to do. It worked at first. haha

Potion code: { private float health; private float maxHealth;

 void Start () 
 {
     maxHealth = 1;    
     health = maxHealth;
 }

 void Update () 
 {
     
 }

 public void GiveHealth(float amount)
 {
     health -= amount;
     if (health <= 0)
         Destroy (gameObject);
 }

}

Player Code with potion reference: { private float speed; public float health; public float maxHealth;

 void Start () 
 {
     speed = 5;
     maxHealth = 3;
     health = maxHealth;
 }

 void Update () 
 {
     float axisX = Input.GetAxis ("Horizontal");
     float axisY = Input.GetAxis ("Vertical");

     transform.Translate(new Vector3(axisX, axisY) * Time.deltaTime * speed);
 }

 void OnCollisionEnter2D(Collision2D coll)
 {
     if (coll.gameObject.tag == "Enemy") 
     {
         health--;

         if (health <= 0)
             Destroy (gameObject);
         coll.gameObject.GetComponent<Enemy> ().ReceiveDamage (1);
     }

     if (coll.gameObject.tag == "Potion") 
     {
         health++;

         if (health <= 0)
             Destroy (gameObject);
         coll.gameObject.GetComponent<Potion> ().GiveHealth (2);
     }



 }

}