Save works for computer but not once i create the build and load it on the android

Not sure what's happening but when I test the game in the editor it works great. Calls the saved score and everything. Once i create the build and put it on my android it the save and load functions no longer work. Here's the code.

using System.Collections; using System.Collections.Generic; using UnityEngine.UI; using UnityEngine; using System; using System.Runtime.Serialization.Formatters.Binary; using System.IO;

public class Start_Screen_UIManager : MonoBehaviour {

 public static Start_Screen_UIManager ssUIManager;



 public Text savedHighScoreText;
 public int savedHighScore = 0;
 

 private void Awake()
 {
  
     if (ssUIManager == null)
     {
         
         ssUIManager = this;
     }

     else if (ssUIManager != this)
     {
         Destroy(gameObject);
     }
     
 }


 private void Start()
 {
     Load();
 }


 public void Update()
 {
     if (savedHighScore < ScoreManager.scoreManager.newHighScore)
     {
         savedHighScore = ScoreManager.scoreManager.newHighScore;
         savedHighScoreText.text = "High Score: " + savedHighScore;
     }
     else
     {
         savedHighScoreText.text = "High Score: " + savedHighScore;
     }


 }

 public void OnDisable()
 {
     Save();
 }

 public void Save()
 {
     BinaryFormatter bf = new BinaryFormatter();
     FileStream file = File.Create(Application.persistentDataPath + "/score.dat");

     ScoreData data = new ScoreData();
     data.score = savedHighScore;
     

     bf.Serialize(file, data);
     file.Close();
 }

 public void Load()
 {
     if (File.Exists(Application.persistentDataPath + "/score.dat"))
     {
         BinaryFormatter bf = new BinaryFormatter();
         FileStream file = File.Open(Application.persistentDataPath + "/score.dat", FileMode.Open);
         ScoreData data = (ScoreData)bf.Deserialize(file);
         file.Close();

         savedHighScore = data.score;
         
         
     }
 }

} [Serializable] class ScoreData { public int score;

}