Unity Android Java Plugin does not work with interface with listener implement

My office has a network library for Android written in Java which enables fast and easy multiplayer networking,

Now, I've been assigned to make the library work on Unity3D, I did my homework on Unity Plugins, AndroidJavaClass, AndroidJavaProxy, AndroidJavaRunnable etc,

So, I can get most Android/Java methods work Like this,

From Java Class -

 Class MyClass{
 public static Helper helperInstance;
 
     Helper() {
         helperInstance = this;
     }
 
     public static Helper GetInstance() {
 
         if (helperInstance == null) {
             helperInstance = new Helper();
         }
 
         return helperInstance;
     }
 
     public Context mContext;
 
     public String Test(Context mContext) {
         this.mContext = mContext;
         Toast.makeText(mContext, "From Java With Love", Toast.LENGTH_SHORT).show();
         return "This Works";
     }
 }

And can access the methods in the class or imported methods from C# like this -

     AndroidJavaClass unityDefault = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
     AndroidJavaObject gameActivity = unityDefault.GetStatic<AndroidJavaObject>("currentActivity");
     AndroidJavaObject context = gameActivity.Call<AndroidJavaObject>("getApplicationContext");
 
     AndroidJavaClass hClass = new AndroidJavaClass("com.nixonok.pluginunity.Helper");
     AndroidJavaObject helperInstance = RightMeshClass.CallStatic<AndroidJavaObject>("GetInstance");
 
     helloText.text = helperInstance.Call<string>("Test", context);

The problem occurs when I implement the listener for network state change listener:

     public interface StateListener {
         int SUCCESS = 1;
         int FAILURE = 2;
         int DISABLED = 3;
         int RESUME = 4;

         void StateChanged(int var1, int var2);
     }

     public Class MyClass implements StateListener{
 // Called By a Service on network event 
 @Override
     public void meshStateChanged(MeshID meshID, int i) {

     }
     Helper() {
                 helperInstance = this;
             }

             public static Helper GetInstance() {

                 if (helperInstance == null) {
                     helperInstance = new Helper();
                 }

                 return helperInstance;
             }

             public Context mContext;

             public String Test(Context mContext) {
                 this.mContext = mContext;
                 Toast.makeText(mContext, "From Java With Love", Toast.LENGTH_SHORT).show();
                 return "Now, Even This doesn't work";
             }

             void init(){
                 nService nn = new nService(mContext, this);
                 // Sending context of the listener impliment to the service
             }
     }

Now, The the plugin won't work at all, Not even the Test method,

implement Interface callback in C# working using AndroidJavaProxy but without the implement, on the Java class, the service won't start :/

Any good idea for me to get this working without needing to change anything in the library?

Thanks in advance :)