when click on hamburger icon sometimes not open navigation drawer but sometime work perfectlySometime issue with click on hamburger icon.Help me solve out this issue.My code is here :- 

activity\_main.xml :- 

```
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">

<android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
     android:fitsSystemWindows="true"
    app:itemBackground="@drawable/drawer_item"
    android:visibility="gone"
    app:headerLayout="@layout/nav_header_main2"
    app:itemTextColor="@color/colorWhite"
    app:menu="@menu/activity_main_drawer" />
</android.support.v4.widget.DrawerLayout>

```

My Kotlin File :- 

```
override fun onNavigationItemSelected(item: MenuItem): Boolean {
    when (item.itemId) {
        R.id.navFormula -> {

        }
    }

    drawer_layout.closeDrawer(GravityCompat.START)
    return true
}

```