ViewPager2 slidet nicht

public class ScheduleRoot2 extends Fragment {


    private static final int NUMBER_PAGES = 4;
    private ViewPager2 objPager2;
    private FragmentStateAdapter objAdapter;




    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View viewRoot = inflater.inflate(R.layout.frag_scheduler2,container,false);


        objPager2 = viewRoot.findViewById(R.id.pager2);
        objAdapter = new ScreenSlideAdapter(getParentFragmentManager(),getLifecycle());
        objPager2.setAdapter(objAdapter);


        return viewRoot;
    }


    private static class ScreenSlideAdapter extends FragmentStateAdapter {


        public ScreenSlideAdapter (FragmentManager fm,Lifecycle ls) {
            super(fm,ls);
        }


        @NonNull
        @Override
        public Fragment createFragment(int position) {
            System.out.println("Pos:" + position);


            switch (position) {
                case 0:
                    return new FragmentA();
                case 1:
                    return new FragmentB();
                case 2:
                    return new FragmentC();
                case 3:
                    return new FragmentD();
            }


            return new FragmentA();
        }


        @Override
        public int getItemCount() {
            return NUMBER_PAGES;
        }
    }
}