从另一个屏幕转到TabLayout内的Android ViewPager后丢失

我的TabLayout和ViewPager在一个片段中。因此，ViewPager在开始时显示片段，但在我从另一个屏幕返回后，ViewPager丢失了

我在我的应用程序上使用buttom导航，如果我第一次单击包含我的ViewPager的菜单，它会工作，但在我单击其他菜单，然后返回ViewPager屏幕后，ViewPager内容会丢失。有人能帮我吗

这是我的适配器：

    public class AdapterTabInfo extends FragmentStatePagerAdapter implements UpperExFragment.OnFragmentInteractionListener, LowerExFragment.OnFragmentInteractionListener {

    int numTabInfo;

    public AdapterTabInfo(FragmentManager fm, int numTabInfo){
        super(fm);
        this.numTabInfo = numTabInfo;
    }

    @NonNull
    @Override
    public Fragment getItem(int position) {
        switch (position){
            case 0:
                UpperExFragment upperExFragment = new UpperExFragment();
                return upperExFragment;
            case 1:
                LowerExFragment lowerExFragment = new LowerExFragment();
                return lowerExFragment;
            default:
                return null;
        }
    }

    public int getCount(){
        return numTabInfo;
    }

    @Override
    public void onFragmentInteraction(Uri uri) {

    }
}

这是我的XML：

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.google.android.material.tabs.TabLayout
            android:id="@+id/info_tab_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:minHeight="?attr/actionBarSize"
            android:theme="@style/Theme.AppCompat.Light.DarkActionBar"
            app:tabIndicatorColor="@color/colorWhite"
            app:tabTextColor="@color/colorWhite"/>

        <androidx.viewpager.widget.ViewPager
            android:layout_below="@id/info_tab_layout"
            android:id="@+id/info_pager"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

        </androidx.viewpager.widget.ViewPager>

    </RelativeLayout>

public InfoFragment() {}

TabLayout tabLayout;
ViewPager viewPager;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View view = inflater.inflate(R.layout.fragment_info, container, false);

    //FindView
    setFindView(view);
    //TabLayout
    setTabLayout();

    return view;
}

@Override
public void onResume() {
    super.onResume();
}

private void setFindView(View view){
    tabLayout = view.findViewById(R.id.info_tab_layout);
    viewPager = view.findViewById(R.id.info_pager);
}

private void setTabLayout(){
    //TabLayout Tabs
    tabLayout.addTab(tabLayout.newTab().setText("Upper Extremity"));
    tabLayout.addTab(tabLayout.newTab().setText("Lower Extremity"));

    //Adapter TabLayout
    AdapterTabInfo adapterTabInfo = new AdapterTabInfo(getActivity().getSupportFragmentManager(), tabLayout.getTabCount());
    viewPager.setAdapter(adapterTabInfo);
    viewPager.setOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));

    //TabLayout OnClick
    tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            viewPager.setCurrentItem(tab.getPosition());
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {

        }

        @Override
        public void onTabReselected(TabLayout.Tab tab) {

        }
    });
}