App crashes when changes are made to preferences on resume

Question

I'm having an issue with my preference page crashing my app. On the first visit, it acts as expected. But as soon as I revisit the page and try to change a switch, the app crashes. Here's what the XML looks like for my preferences:

    xmlns:app="http://schemas.android.com/apk/res-auto">

    <PreferenceCategory
        android:gravity="left"
        android:title="@string/description_title"
        app:iconSpaceReserved="false">

        <SwitchPreference
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:key="@string/pallet_pref_key"
            android:title="@string/pallet_pref"
            app:iconSpaceReserved="false" />
        <SwitchPreference
            android:key="@string/nose_pref_key"
            android:title="@string/nose_pref"
            app:iconSpaceReserved="false" />
        <SwitchPreference
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:key="@string/finish_pref_key"
            android:title="@string/finish_pref"
            app:iconSpaceReserved="false" />
    </PreferenceCategory>

</PreferenceScreen>

The Java looks like this:

import android.os.Bundle;
import androidx.appcompat.app.ActionBar;
import androidx.appcompat.app.AppCompatActivity;
import androidx.preference.PreferenceFragmentCompat;
import androidx.preference.PreferenceManager;
import androidx.preference.SwitchPreference;

public class SettingsActivity extends AppCompatActivity {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.settings_activity);

        getSupportFragmentManager()
                .beginTransaction()
                .replace(R.id.settings, new SettingsFragment())
                .commit();
        ActionBar actionBar = getSupportActionBar();
        if (actionBar != null) {
            actionBar.setDisplayHomeAsUpEnabled(true);
        }

    }

    public static class SettingsFragment extends PreferenceFragmentCompat {

        private SharedPreferences sharedPref;
        private boolean pNose;
        private boolean pPallet;
        private boolean pFinish;

        @Override
        public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
            setPreferencesFromResource(R.xml.root_preferences, rootKey);
            sharedPref = PreferenceManager.getDefaultSharedPreferences(getActivity());
            sharedPref.registerOnSharedPreferenceChangeListener(new SharedPreferences.OnSharedPreferenceChangeListener() {
                @Override
                public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String s) {
                    if(s.equals(getResources().getString(R.string.pallet_pref_key))) {
                        pPallet = sharedPreferences.getBoolean(s,false);
                        SwitchPreference pNose = findPreference(getResources().getString(R.string.nose_pref_key));
                        SwitchPreference pFinish = findPreference(getResources().getString(R.string.finish_pref_key));
                        if (pPallet) {
                            pNose.setChecked(false);
                            pFinish.setChecked(false);
                        }
                    }
                    else if(s.equals(getResources().getString(R.string.nose_pref_key))) {
                        pNose = sharedPreferences.getBoolean(s,false);
                        SwitchPreference pPallet = findPreference(getResources().getString(R.string.pallet_pref_key));
                        SwitchPreference pFinish = findPreference(getResources().getString(R.string.finish_pref_key));
                        if (pNose) {
                            pPallet.setChecked(false);
                            pFinish.setChecked(false);
                        }
                    }
                    else if(s.equals(getResources().getString(R.string.finish_pref_key))) {
                        pFinish = sharedPreferences.getBoolean(s,false);
                        SwitchPreference pPallet = findPreference(getResources().getString(R.string.pallet_pref_key));
                        SwitchPreference pNose = findPreference(getResources().getString(R.string.nose_pref_key));
                        if (pFinish) {
                            pNose.setChecked(false);
                            pPallet.setChecked(false);
                        }
                    }
                }
            });
        }
    }
}

So basically I'm just trying to make it so only one switch can be enabled at a time. I did some research and found a few threads on here that mentioned I should add this code:

@Override
protected void onResume() {
    super.onResume();
    // Set up a listener whenever a key changes
    getPreferenceScreen().getSharedPreferences()
            .registerOnSharedPreferenceChangeListener(this);
}

@Override
protected void onPause() {
    super.onPause();
    // Unregister the listener whenever a key changes
    getPreferenceScreen().getSharedPreferences()
            .unregisterOnSharedPreferenceChangeListener(this);
}

I'm thinking that's probably the reason for the crash, but when I add that code below the "OnSharedPreferenceChangeListener() {" statement onResume() and onPause() are greyed out unless I hoist it to the top in which case the this keyword throws an error. Does anyone see what I'm doing wrong?

Here's the error that I get on the crash: