Power up not working

So I currently have a working 'Speed' power up that multiplies the speed of the player by 2. I'm trying to make a power up now that increases the score you get for picking up the GameObject 'Gem' by 2. it should increase to 20 points per gem from 10.

Currently, the power up is spawning randomly around the map within 10-20 seconds, so as intended, but the score you get for collecting the power up has not gone up to 20.

PlayerMovement Code:

 void OnTriggerEnter2D(Collider2D other)
 {
     if (other.gameObject.CompareTag ("shuriken")) 
     {
         if (livess <= 1) 
         {
             Destroy (Player);
             livess = livess - 1;
             Debug.LogError (livess);
         } 
         else 
         {
             livess = livess - 1;
             Debug.LogError (livess);
             return;
         }
     } 
     if (other.gameObject.CompareTag ("speedPowerUp")) 
     {
         StartCoroutine (WaitTimeSpeed ());
         other.gameObject.SetActive (false);
     }
     if (other.gameObject.CompareTag ("MultiPowerUp")) 
     {
         StartCoroutine (WaitTimeMulti ());
         other.gameObject.SetActive (false);
     }
 IEnumerator WaitTimeMulti()
 {
     addScore = 20;
     yield return new WaitForSeconds (5);
     addScore = 10;
     yield return new WaitForSeconds (Random.Range (10, 20));
     SpawnMulti ();
 }
 void SpawnMulti ()
 {
     Vector3 RandomSpawn = new Vector3 (Random.Range (-8.87F, 8.87F), Random.Range (-3.87F, 3.97F),1F);
     Instantiate (MultiPowerUp, RandomSpawn, Quaternion.identity);
 }

Gem script:

 public GameObject Gem;
 public static int count;
 public Text countText;
 public int addScores = PlayerMovement.addScore;

 void Start()
 {
     SetCountText ();
 }

 void SpawnGem()
 {
     Vector3 RandomSpawn = new Vector3 (Random.Range (-8.87F, 8.87F), Random.Range (-3.87F, 3.97F),1F);
     Instantiate (Gem, RandomSpawn, Quaternion.identity);
 }
 void OnTriggerEnter2D(Collider2D other)
 {
     if (other.gameObject.CompareTag ("Player")) 
     {
         SpawnGem ();
         Destroy (Gem);
         count = count + addScores;
         SetCountText ();
         PlayerPrefs.SetInt("Player Score", count); 
     }
 }
 void SetCountText()
 {
     countText.text = "Count: " + count.ToString ();
 }

}