Ограничения в Моно для разработчика инфраструктуры .NET

Попробуйте это

activity_main.xml

<android.support.design.widget.CoordinatorLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">


<FrameLayout
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" />

<android.support.design.widget.BottomNavigationView
    android:id="@+id/navigation"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom"
    android:background="?android:attr/windowBackground"
    app:itemBackground="@color/bottamNav"
    android:foreground="?attr/selectableItemBackground"
    app:itemIconTint="@color/colorAccent"
    app:itemTextColor="@color/colorAccent"
    app:menu="@menu/navigation_menu" />

 </android.support.design.widget.CoordinatorLayout>

menu / navigation_menu.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android">

<item
    android:id="@+id/navigation_home"
    android:icon="@drawable/ic_home"
    android:title="@string/title_shop"
    />

<item
    android:id="@+id/navigation_watch"
    android:icon="@drawable/ic_shopping_cart"
    android:title="@string/title_offer" />

<item
    android:id="@+id/navigation_download"
    android:icon="@drawable/ic_wallet"
    android:title="@string/title_order" />

</menu>

MainActivity.java [ 117]

public class MainActivity extends AppCompatActivity {
  BottomNavigationView navi;
  FragmentTransaction fragmentTransaction;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    navi = findViewById(R.id.navigation);

    switchFragment(new HomeFragment());

    navi.setOnNavigationItemSelectedListener(item -> {
        Fragment fragment;
        if (item.getItemId() == R.id.navigation_home) {
            fragment = new HomeFragment();
            switchFragment(fragment);
            return true;
        } else if (item.getItemId() == R.id.navigation_watch) {
            fragment = new WatchLaterFragment();
            switchFragment(fragment);
            return true;
        } else if (item.getItemId() == R.id.navigation_download) {
            fragment = new DownloadsFragment();
            switchFragment(fragment);
            return true;
        }
        return false;
    });
  }
  private void switchFragment(Fragment fragment) {
    fragmentTransaction = getSupportFragmentManager().beginTransaction();
    fragmentTransaction.replace(R.id.container, fragment);
    fragmentTransaction.addToBackStack(null);
    fragmentTransaction.commit();
  }
}

обновление

перейти к вашему файлу Menifest. В своей деятельности просто установите HardwareAccelerated true, чтобы предотвратить задержку открытия ящика

 <activity
    android:name=".MainActivity"
    android:hardwareAccelerated="true"  
    >
    ...........
    ...........
 </activity>