Nested tabs doesn't load contents and freezes

The application contains 3 tabs - Home, About and FAQ. Within About tab, I've 2 more tabs namely - User details and Privacy Policy. Each of these will load a fragment into viewpager. Below is relevant code I am having now.

HomeActivity.java

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);
    Intent intentData = getIntent();
    initUI();
}

private void initUI() {
    final ViewPager viewPager = (ViewPager) findViewById(R.id.vp_horizontal_ntb);
    ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
    adapter.addFrag(new HomeFragment(), "Home");
    adapter.addFrag(new AboutFragment(), "About");
    adapter.addFrag(new FAQFragment(), "FAQ");
    viewPager.setAdapter(adapter);
    final NavigationTabStrip navigationTabStrip = (NavigationTabStrip) findViewById(R.id.nts_bottom);
    navigationTabStrip.setViewPager(viewPager, 0);
}

AboutFragment.java

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    final View view=inflater.inflate(R.layout.fragment_about, container, false);
    new Thread(new Runnable() {
        @Override
        public void run() {
            initUI(view);
        }
    }).start();

    return view;
}
private void initUI(View view) {
    final ViewPager viewPager = (ViewPager) view.findViewById(R.id.about_horizontal_tab);
    ViewPagerAdapter adapter = new ViewPagerAdapter(getActivity().getSupportFragmentManager());
    adapter.addFrag(new UserDetailsFragment(), "User Details");
    adapter.addFrag(new PrivacyPolicyFragment(), "Privacy Policy");
    viewPager.setAdapter(adapter);
    final NavigationTabStrip navigationTabStrip = (NavigationTabStrip) view.findViewById(R.id.nts_top);
    navigationTabStrip.setViewPager(viewPager, 0);
}

ViewPagerAdapter.java

public class ViewPagerAdapter extends FragmentPagerAdapter {
    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();

    public ViewPagerAdapter(FragmentManager manager) {
        super(manager);
    }

    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }

    @Override
    public int getCount() {
        return mFragmentList.size();
    }

    public void addFrag(Fragment fragment, String title) {
        mFragmentList.add(fragment);
        mFragmentTitleList.add(title);
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return mFragmentTitleList.get(position);
    }
}

But contents within About tab's, User Details and Privacy Policy never loads even though, when debugged, it hits the respective fragment's onCreateView method. Similarly, when I navigate to Privacy Policy tab it gets stuck there and doesn't navigate back to User Details tab on click.

How could I possibly solve this issue? Is it supported to have nested tabs in android?

Devlight / NavigationTabStrip

Nested tabs doesn't load contents and freezes #25