Explicitly starting activity from menu item not working

Question

using android 2.3.3 and Android API 25.

having 3 activities activity_main , activity_details and activity_settings. I've used android studio auto generating for creating these activities as blank activity with fragment, So manifest code is generated automatically.

activity_main and activity_details have menu option Settings that's for opening the activity_settings.

clicking on Settings option menu for activity_details works and opens activity_settings but not working for activity_main

and here is my code:

MainActivityFragment.java and DetailActivityFragment.java (same)

`@Override
public boolean onOptionsItemSelected(MenuItem item) {
    if (item.getItemId() == R.id.action_settings) {
        startActivity(new Intent(getActivity(), SettingsActivity.class));
        return true;
    }
}`

menu_detail.xml

`<menu 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"
    tools:context="com.example.poula.sunshine.DetailActivity">
    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        android:title="Settings"
        app:showAsAction="never" />
</menu>`

menu_main.xml

`<menu 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"
    tools:context="com.example.poula.sunshine.MainActivity" >
    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        android:title="Settings"
        app:showAsAction="never" />
</menu>`