How to preserve manually set InstanceState of ViewPager Fragments (in depth explanation)?

Question

I have a ViewPager (instantiated with FragmentStatePagerAdapter) with some Fragment attached to it.

In a specific usecase I need to reset instanceBean and UI for most of the fragments in the pager.

After some googling I have tried some solutions like this but the side effects were not easy manageable. Other solution like this doesn't match my needs.

So I decided to go straight with the manual reset of the UI and instanceBean obj like in the code below:

The code

Single fragment reset

public void initFragment() {
    notaBean = new NoteFragmentTO();
    
    fromSpinnerListener = false;
}

public void resetFragment() {
    initFragment();
    NoteFragment.retainInstanceState = false;
}

This is done with the following code from the parent Activity:

Fragment reset from parent

    private void resetAfterSaving() {
    mIndicator.setCurrentItem(POSITION_F*****);
    f*****Info.resetFragment();
    
    mIndicator.setCurrentItem(POSITION_NOTE);
    noteInfo.resetFragment();
    
    mIndicator.setCurrentItem(POSITION_M*****);
    m*****Info.resetFragment();
    
    mIndicator.setCurrentItem(POSITION_V*****);
    v*****.resetFragment();
}

AfterViews method:

    @AfterViews
    public void afterView() {
        if (mSavedInstanceState != null) {
            restoreState(mSavedInstanceState);
        }

        NoteFragment.retainInstanceState = true;
        
        // Inits the adapters
        noteAdapter = new NoteArrayAdapter(this, noteDefaultList);

        sp_viol_nota_default.setAdapter(noteAdapter);
        //sp_viol_nota_default.seton
        
        et_viol_nota.setOnFocusChangeListener(new OnFocusChangeListener() {

            @Override
            public void onFocusChange(View v, boolean hasFocus) {
                if (!hasFocus) {
                    String readText = et_viol_nota.getText().toString().trim();
                    
                    notaBean.setNota(readText == "" ? null : readText);
                }
            }
        });
    }

OnSavedInstanceState

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    
    outState.putParcelableArrayList(KEY_NOTE_D_LIST, (ArrayList<VlzAnagraficaNoteagente>) noteDefaultList);
    outState.putInt(KEY_NOTE_D_POSITION, !NoteFragment.retainInstanceState ? 0 : notePosition);

    notaBean.setNota(!NoteFragment.retainInstanceState ? "" : et_viol_nota.getText().toString().trim());
    outState.putParcelable(NoteFragmentTO.INTENT_KEY, notaBean);
}

---

Why do I set every page before resetting them?

Because like explained here:

When pages are not visible to the user, their entire fragment may be destroyed, only keeping the saved state of that fragment.

and because until I don't select the relative fragment the @AfterViews method (that is everything processed right after OnCreateView of the fragment) is not executed. This throws NullPointerException for a thousand of reason (Usually in the @AfterViews method You launch RestoreState method, initializes adapter, do UI stuff).

Setting the relative page before the reset let @AfterViews method be processed.

---

Before checking what would happened when rotating the device, all the fragment I need are correcly reset.

When rotating the device, the error comes out:

The views (mainly EditText) go back to their previous state BEFORE my reset.

What happens?

When switching between the page, at a certain point the page will be destroyed and OnSavedInstanceState is called everytime for each page.

I have already handled the OnSavedInstanceState (like above) that when the boolean is false saves the state like if it had just been created.

I found that until within AfterView method the EditText has its text set to blank (like I want) but going on with the debug the EditText goes back to its previous state, so at the end it will show the last text it had.

Question

How can I keep the manually set (in OnSavedInstanceState) EditText text after destroying/recreating a fragment?