Why is changing fragments hiding my tablayout (android)?

I have two fragments in my application. fA and fb. fA has a toolbar, tab layout and viewer. fB has text representation and image. When I click on any button in fA on any pager, it opens fB and displays an image with some text. It opens everything fine, but when I click back to go back to my first snippet, I lose the tab layout. Space for tabs is present, but there is no indicator or title. Can anyone please help?

My fA xml:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout 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"
    android:clipToPadding="false"
    android:fitsSystemWindows="true">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/primary"
        android:clipToPadding="false"
        android:elevation="4dp" />

    <android.support.design.widget.TabLayout
        android:id="@+id/tab_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/primary"
        android:clipToPadding="false"
        android:elevation="4dp"
        android:paddingEnd="0dp"
        android:paddingStart="48dp"
        android:layout_marginTop="56dp"
        android:scrollbars="horizontal"
        app:tabGravity="center"
        app:tabIndicatorColor="@android:color/white"
        app:tabMode="scrollable"
        app:tabTextColor="@color/primary_text" />

    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clipToPadding="false" />

</FrameLayout>

      

        
        
        
      

    

and my class:

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.tab_fragment, container, false);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        titles = getTitles();

        MainActivity parent = (MainActivity) getActivity();
        parent.setToolbar((Toolbar) view.findViewById(R.id.toolbar));

        viewPager = (ViewPager) view.findViewById(R.id.viewPager);
        stateListener = parent.getViewPagerStateListenerInstance();
        viewPager.setAdapter(new PagerAdapter(getChildFragmentManager()));
        viewPager.addOnPageChangeListener(stateListener);

        TabLayout tabLayout = (TabLayout) view.findViewById(R.id.tab_layout);
        tabLayout.setupWithViewPager(viewPager);
        parent.setUpTabLayout(tabLayout);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        viewPager.removeOnPageChangeListener(stateListener);
    }

      

        
        
        
      

    

My toolbar and tab layout are in a snippet and need to be replaced.

Any help is appreciated. Thank you.