fitsSystemWindows not working in fragments added by FragmentPagerAdapter

My app is working with a FragmentPagerAdapter to add Fragments to the ViewPager. The problem is that the property android:fitsSystemWindows="true" ist not working. It doesn't add padding to the elements.

My main layout looks like following:

<android.support.constraint.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.TabLayout
        android:id="@+id/viewPagerTab"
        android:layout_width="0dp"
        android:layout_height="48dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:tabIndicatorColor="@android:color/transparent"/>

    <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toTopOf="@+id/viewPagerTab"/>
</android.support.constraint.ConstraintLayout>

I set my adapter and add the fragments.

    MainPagerAdapter adapter = new MainPagerAdapter(getSupportFragmentManager());
    adapter.addFragment(new TestFragment(), "Test");
    adapter.addFragment(new GroupFragmentManager(), "Group");
    adapter.addFragment(new ProfileFragment(), "User");
    viewPager.setAdapter(adapter);

    viewPagerTab.setupWithViewPager(viewPager);

My pager looks like this:

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

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

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

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

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

The layout of the ProfileFragment just has simple test stuff in it.

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:fitsSystemWindows="true">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Profile"
        android:fitsSystemWindows="true"/>
</LinearLayout>

But it will still not draw a padding. I also have set the right styles.

<style name="Base.Theme.SnowLink" parent="Theme.AppCompat.Light.DarkActionBar">
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">#FF4081</item>
    <item name="windowActionBar">false</item>
    <item name="windowNoTitle">true</item>

    <item name="android:windowTranslucentStatus">true</item>
    <item name="android:windowTranslucentNavigation">true</item>
</style>

I searched and tested a lot. I think android has some problems with the loaded fragments, because it works in the activity layout. I also use databinding.

Thanks in advance!