Android Studio导航抽屉片段重叠

我已经将导航抽屉活动添加到我的项目中，并且试图将项目添加为片段。这是我在主要活动中所做的。

fragmentManager = getSupportFragmentManager();
        fragmentTransaction = fragmentManager.beginTransaction();
        fragmentTransaction.add(R.id.nav_host_fragment, new HomeFragment());
        fragmentTransaction.commit();

        navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
            @Override
           public boolean onNavigationItemSelected(@NonNull MenuItem item)
            {
                DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
                drawer.closeDrawer(GravityCompat.START);
                int id = item.getItemId();
                if (id == R.id.nav_home)
                {
                    fragmentManager = getSupportFragmentManager();
                    fragmentTransaction = fragmentManager.beginTransaction();
                    fragmentTransaction.replace(R.id.nav_host_fragment, new HomeFragment());
                    fragmentTransaction.commit();

                }
                else if(id == R.id.Shopping_list)
                {
                    fragmentManager = getSupportFragmentManager();
                    fragmentTransaction = fragmentManager.beginTransaction();
                    fragmentTransaction.replace(R.id.nav_host_fragment, new ShoppingListFragment());
                    fragmentTransaction.commit();
                }
                else if(id == R.id.nav_Language)
                {
                    fragmentManager = getSupportFragmentManager();
                    fragmentTransaction = fragmentManager.beginTransaction();
                    fragmentTransaction.replace(R.id.nav_host_fragment, new FragmentLang());
                    fragmentTransaction.commit();
                }

默认片段是Home，它工作正常，但是可以预期，其他片段与Home Fragment重叠。（HomeFragment是唯一运行良好的工具）。我在每个Fragment类中都做了这样的事情：

public class ShoppingListFragment extends Fragment{
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
   View view = inflater.inflate(R.layout.fragment_shopping_list, container,false);
   return view;
    }

}

我看不出错误在哪里！一切看起来不错，但所有其他片段都显示在HomeFragment上。

你能帮忙吗？