Fragment not Opening Previous Fragment on Back Button

Question

I have been struggling to implement a super simple app layout, where my MainActivity opens Fragment#1 in its onCreate method, then the Fragment#1 opens Fragment#2 when an item is clicked.

As of right now, when I open Fragment#1 from my MainActivity, I add Fragment#1 to the BackStack. After opening Fragment#2, when I hit the back button the first click does nothing, then the second click sends me all the way back to my login page, skipping past Fragment #1 and MainActivity.

How can I make it so when I hit the back button on Fragment#2, it opens Fragment#1 back up?

(MainActivity opens Fragment#1)

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        SearchListFragment fragment = new SearchListFragment();
        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
        transaction.replace(R.id.main_fragment_container, fragment);
        transaction.addToBackStack(TAG);
        transaction.commit();

    }
}

(Fragment#1 opens Fragment#2)

public class SearchListFragment extends Fragment {

    public void viewResults(SearchModel search) {
        Bundle args = new Bundle();
        args.putString("ID", search.getId());
        ResultsFragment fragment = new ResultsFragment();
        fragment.setArguments(args);
        FragmentTransaction transaction = getParentFragmentManager().beginTransaction();
        transaction.replace(R.id.main_fragment_container, fragment);
        transaction.commit();
    }
}

EDIT

I should have mentioned that I have tried to handle the back press event myself. I tried adding this to my MainActivity but it did not change the behavior:

@Override
    public void onBackPressed() {
        if (getSupportFragmentManager().getBackStackEntryCount() == 0) {
            this.finish();
        } else {
            getSupportFragmentManager().popBackStack();
        }
    }

Answer 1

getSupportFragmentManager().beginTransaction().replace(R.id.frag_frame, fragment).addToBackStack("text").commit();

Answer 2

onCreate with

Kotlin

   val backpress = requireActivity().onBackPressedDispatcher.addCallback(viewLifecycleOwner, true) {
                        // Handle the back button event

}

Java

    OnBackPressedCallback callback = new OnBackPressedCallback(true /* enabled by default */) {
        @Override
        public void handleOnBackPressed() {
            // Handle the back button event
        }
    });
    requireActivity().getOnBackPressedDispatcher().addCallback(this, callback);

You can provide your back operations in the relevant sections.