почему страница заметок не отображается и не может синхронизироваться

Question

My purpose: I am using Realm as a database and I am making a note app .I suppose note page can be saved and there is new info (a new column) in the mainActivity .However , after clicking the Save button in the action bar . These can't work but no error is made . 

Какие файлы у меня есть? 1.RealmBasicConfig 2.AddSaveNotesActivity 3.NotesAdapter 4.notes_rv_layout (для предустановленного представления первой заметки) 5.MainActivity (первая страница в приложении)

Какие решения я хочу: почему не работает notes_rv_layout, и содержимое заметок не может быть синхронизировано. Это должна быть проблема mainActivity (адаптер !!. notifyDataSetChanged - не работает?)

Коды MainActivity:

class Main2Activity : AppCompatActivity() {
    private lateinit var notesList:ArrayList<BasicInfoConfig>
    private lateinit var realm: Realm
    private lateinit var appBarConfiguration: AppBarConfiguration



    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main2)
        handleIntent(intent)
        val toolbar: Toolbar = findViewById(R.id.toolbar)
        setSupportActionBar(toolbar)

        val drawerLayout: DrawerLayout = findViewById(R.id.drawer_layout)
        val navView: NavigationView = findViewById(R.id.nav_view)
        val navController = findNavController(R.id.nav_host_fragment)
        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        appBarConfiguration = AppBarConfiguration(setOf(
                R.id.nav_home, R.id.nav_gallery, R.id.nav_slideshow), drawerLayout)
        setupActionBarWithNavController(navController, appBarConfiguration)
        navView.setupWithNavController(navController)

        //custom init views
        realm  = Realm.getDefaultInstance()



        //set onclicklistener
        addNotes.setOnClickListener{
            startActivity(Intent(this,AddSaveNotesActivity::class.java))
            finish()

        notesRV.layoutManager = LinearLayoutManager(this)
        getAllNotes()
        }

    }

    private fun getAllNotes() {  //yellow : used
        notesList = ArrayList()
        val  results:RealmResults<BasicInfoConfig> = realm.where<BasicInfoConfig>(BasicInfoConfig::class.java).findAll()
        notesRV.adapter = NotesAdapter(this,results)
        notesRV.adapter!!.notifyDataSetChanged()   // to update   // bec  I deleted the way it saved // none info can be read
    }

    override fun onNewIntent(intent: Intent) {
        super.onNewIntent(intent)

        handleIntent(intent)
    }


    override fun onCreateOptionsMenu(menu: Menu): Boolean {
        // Inflate the menu; this adds items to the action bar if it is present.
        menuInflater.inflate(R.menu.main2, menu)
        // Associate searchable configuration with the SearchView
        // Associate searchable configuration with the SearchView
        val searchManager = getSystemService(Context.SEARCH_SERVICE) as SearchManager
        (menu.findItem(R.id.search).actionView as SearchView).apply {
            setSearchableInfo(searchManager.getSearchableInfo(componentName))
        }
        return true
    }

    override fun onBackPressed() {

        super.onBackPressed()
    }

    override fun onSupportNavigateUp(): Boolean {
        val navController = findNavController(R.id.nav_host_fragment)
        return navController.navigateUp(appBarConfiguration) || super.onSupportNavigateUp()
    }
    private fun handleIntent(intent: Intent) {

        if (Intent.ACTION_SEARCH == intent.action) {
         val query = intent.getStringExtra(SearchManager.QUERY)
            //use the query to search your data somehow
        }
    }
}

коды NotesAdapterView

class NotesAdapter (private val context : Context? , private  val notesList : RealmResults<BasicInfoConfig>)
    : RecyclerView.Adapter<RecyclerView.ViewHolder>(){

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        val v = LayoutInflater.from(parent.context).inflate(R.layout.notes_rv_layout, parent,false)
        return ViewHolder(v)
    }

    override fun getItemCount(): Int {
        return notesList.size
    }

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
            holder.itemView.notes_title.text = notesList[position]!!.title
            holder.itemView.notes_body.text = notesList[position]!!.description


    }
    class  ViewHolder(v:View?):RecyclerView.ViewHolder(v!!) {
        //
        val Ada_title = itemView.findViewById<TextView>(R.id.notes_title)
        val Ada_date = itemView.findViewById<TextView>(R.id.notes_timeStamp)
    }

Коды RealmBasicConfig:

package com.example.notepad_free

import io.realm.RealmObject
import io.realm.annotations.PrimaryKey

open class BasicInfoConfig(
//connecting  basic info to Realm
    @PrimaryKey

var id:Int ?= null,
var title:String?=null,
var description:String?=null


):RealmObject()

Скажите, пожалуйста, если нужны дополнительные коды, буду благодарен, если вы поможете!