碎片已泄漏，尽管已连接

Question

我在MainActivity上使用带有4个片段的BottomNavigationView。另外，我使用LeakCanary检查内存泄漏，虽然没有分离并且它的托管活动没有销毁，但我收到了这个Fragment泄漏。

* org.kafora.apps.qutoof.ui.main.home.HomeFragment has leaked:
* static ActivityThread.sCurrentActivityThread
* ↳ ActivityThread.mActivities
* ↳ ArrayMap.mArray
* ↳ array Object[].[3]
* ↳ ActivityThread$ActivityClientRecord.activity
* ↳ MainActivity.!(mHomeFragment)!
* ↳ HomeFragment

泄漏跟踪详细信息： https://drive.google.com/file/d/1Kd82el7z_82AVLfYDrhfEW7tV50kcrQP/view?usp=sharing

这是MainActivity类：

public class MainActivity extends MediaBaseActivity implements BottomNavigationView.OnNavigationItemSelectedListener
        , BottomNavigationView.OnNavigationItemReselectedListener {

    private static final String TAG = MainActivity.class.getSimpleName();
    private FragmentManager fragmentManager;
    private BrowseFragment mBrowseFragment;
    private HomeFragment mHomeFragment;
    private LibraryFragment mLibraryFragment;
    private ReminderFragment mReminderFragment;

    private Unbinder unbinder;
    @BindView(R.id.parentView)
    View parentView;
    @BindView(R.id.toolbar)
    Toolbar toolbar;
    @BindView(R.id.bottom_nav_view) BottomNavigationView bottomNavView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        unbinder = ButterKnife.bind(this);
        fragmentManager = getSupportFragmentManager();
        displayInitialHomeFragment();
        setSupportActionBar(toolbar);
        setupBottomNavigationView(); 
    }
    private HomeFragment getHomeFragment(){
        if(mHomeFragment == null) mHomeFragment = HomeFragment.newInstance();
        return mHomeFragment;
    }

    private BrowseFragment getBrowseFragment(){
        if(mBrowseFragment == null) mBrowseFragment = BrowseFragment.newInstance();
        return mBrowseFragment;
    }
    private LibraryFragment getLibraryFragment(){
        if(mLibraryFragment == null) mLibraryFragment = LibraryFragment.newInstance();
        return mLibraryFragment;
    }
    private ReminderFragment getReminderFragment(){
        if(mReminderFragment == null) mReminderFragment = ReminderFragment.newInstance();
        return mReminderFragment;
    }

    private void displayInitialHomeFragment() {
        if (fragmentManager.findFragmentById(R.id.frame_container) == null) {
            fragmentManager.beginTransaction().add(R.id.frame_container, getHomeFragment()).commit();
        }
    }

    private void displaySelectedFragment(Fragment fragment) {
        if (fragment != fragmentManager.findFragmentById(R.id.frame_container)) {
            fragmentManager.beginTransaction()
                    .replace(R.id.frame_container, fragment)
                    .commit();
        }
    }

    public void setupBottomNavigationView() {
      bottomNavView.setOnNavigationItemSelectedListener(this);
      bottomNavView.setOnNavigationItemReselectedListener(this);
    }


    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
        int id = item.getItemId();
        switch (id) {
            case R.id.home:
                displaySelectedFragment(getHomeFragment());
                return true;
            case R.id.browse:
                displaySelectedFragment(getBrowseFragment());
                return true;
            case R.id.library:
                displaySelectedFragment(getLibraryFragment());
                return true;
            case R.id.reminder:
                displaySelectedFragment(getReminderFragment());
                return true;
            default:
                return false;
        }
    }

    @Override
    public void onNavigationItemReselected(@NonNull MenuItem item) {

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbinder.unbind();
        mHomeFragment= null;
        mBrowseFragment = null;
        mReminderFragment = null;
        mLibraryFragment = null;
    }
}

此内存泄漏的原因是什么？