SharedPreferences resetting when app closes

Question

I have a ListView fragment that has the option to save specific table values. You can click a button to toggle the table to only show saved values. When the toggle is active instead of saving you have the option to delete values. I have noticed however that while the delete will delete the value permanently so long as the app is open, If i close the app and reopen it, the value will reappear. Also if I delete the app and reinstall this same value reappears. I'm not sure how this value is getting added in and why it refuses to go. Debugging shows me saving the correct values in SharedPreferences but that does not stay.

EDIT: After some more testing it appears that the first item saved in the specific SharedPreferences remains permanently saved. It cannot be removed and all other values saved will not remain there.

Fragment:

package layout;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.preference.PreferenceManager;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.widget.SwipeRefreshLayout;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.TextView;
import android.os.StrictMode;
import com.tble.brgo.HTMLPull;
import com.tble.brgo.InfoArticle;
import com.tble.brgo.R;
import android.widget.AdapterView.OnItemClickListener;
import java.io.IOException;
import java.lang.reflect.Array;
import java.util.ArrayList;
import android.text.TextUtils;
import java.util.HashSet;
import java.util.Set;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link Websites#newInstance} factory method to
 * create an instance of this fragment.
 */
public class Websites extends Fragment implements SearchView.OnQueryTextListener, displayInterface {
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private SearchView mSearchView;
    private ListView mListView;
    public Boolean toggle = false;
    public ArrayList<InfoArticle> mData = new ArrayList<InfoArticle>();
    public StandardCellAdapter mAdapter;
    public ArrayList<InfoArticle> fDataSet = new ArrayList<InfoArticle>();
    public Websites webTable;
    public Websites() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @return A new instance of fragment Websites.
     */
    // TODO: Rename and change types and number of parameters
    public static Websites newInstance() {
        Websites fragment = new Websites();
        Bundle args = new Bundle();
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        toggle = false;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_websites, container, false);
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                .permitAll().build();
        StrictMode.setThreadPolicy(policy);
        ArrayList<InfoArticle> data = new ArrayList<InfoArticle>();
        webTable = this;
        try {
            data = getData();
        } catch (IOException e) {
            e.printStackTrace();
        }

        mListView = (ListView) view.findViewById(R.id.WebsiteTable);
        final StandardCellAdapter adapter = new StandardCellAdapter(getActivity(), data, 1,this);
        fDataSet = data;
        mData = data;
        mListView.setAdapter(adapter);
        mAdapter = adapter;
        mSearchView = (SearchView) view.findViewById(R.id.searchView);
        mListView.setTextFilterEnabled(true);
        FloatingActionButton myFab = (FloatingActionButton) view.findViewById(R.id.dataToggle);
        myFab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
            toggleView();
            }
        });
        setupSearchView();
        final SwipeRefreshLayout swipeLayout = (SwipeRefreshLayout) view.findViewById(R.id.webRefresh);
        swipeLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                try {
                    mData = getData();
                    mAdapter = new StandardCellAdapter(getContext(), mData, 1,webTable);
                    mListView.setAdapter(mAdapter);
                } catch (IOException e) {
                    e.printStackTrace();
                }
                swipeLayout.setRefreshing(false);
            }
        });
        return view;
    }

    private void setupSearchView() {
        mSearchView.setOnQueryTextListener(this);
        mSearchView.setIconifiedByDefault(true);
    }

    private ArrayList<InfoArticle> getData() throws IOException {
        SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
        int school = sharedPref.getInt("School", 14273);
        HTMLPull Connection = new HTMLPull();
        Connection.getStaff(school);
        Connection.Results.remove(0);
        return Connection.Results;
    }

    @Override
    public boolean onQueryTextChange(String newText) {

        if (TextUtils.isEmpty(newText)) {
            mListView.clearTextFilter();
        } else {
            mListView.setFilterText(newText);
        }
        return true;
    }

    public ArrayList<InfoArticle> toData(ArrayList<String> t, ArrayList<String> d) {
        ArrayList<InfoArticle> temp = new ArrayList<InfoArticle>();
        if (t.size() == 0) {
            temp.add(new InfoArticle("Slide to Save Teachers", "google.com"));
        } else {
            for (int i = 0; i < t.size(); i++) {
                temp.add(new InfoArticle(t.get(i), d.get(i)));
            }
        }
        return temp;
    }


    @Override
    public boolean onQueryTextSubmit(String query) {
        return false;
    }
    private void toggleView(){
        if (!toggle) {
            SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
            HashSet<String> defv = new HashSet<String>();
            ArrayList<String> teachers = new ArrayList<String>(sharedPref.getStringSet("teachPref", defv));
            ArrayList<String> links = new ArrayList<String>(sharedPref.getStringSet("linkPref", defv));
            mAdapter = new StandardCellAdapter(getContext(), toData(teachers, links),2,this);
            mListView.setAdapter(mAdapter);
            toggle = true;
        } else {
            mAdapter = new StandardCellAdapter(getContext(), mData, 1,this);
            mListView.setAdapter(mAdapter);
            toggle = false;
        }
    }
    /**public void displayWebpage(int position){
        if (toggle == true) {
            WebsiteDisplay fullView = WebsiteDisplay.newInstance(mAdapter.getItem(position).description);
            FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
            transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
        } else {
            if (!mSearchView.isIconified()) {
                for (InfoArticle a : fDataSet) {

                    if (a.title.equals(((InfoArticle) mListView.getAdapter().getItem(position)).title)) {
                        WebsiteDisplay fullView = WebsiteDisplay.newInstance(a.description);
                        FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
                        transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
                    }
                }
            } else {
                WebsiteDisplay fullView = WebsiteDisplay.newInstance(fDataSet.get(position).description);
                FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
                transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
            }
        }
    }*/
    public void displayWebpage(String Link){
        WebsiteDisplay fullView = WebsiteDisplay.newInstance(Link);
        FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
        transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
    }
}

CellAdapter:

package layout;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.media.Image;
import android.nfc.Tag;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.widget.RecyclerView;
import android.widget.ArrayAdapter;
import android.content.Context;
import android.view.View;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Set;
import android.preference.PreferenceManager;
import android.widget.ImageView;
import android.widget.TextView;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import com.chauthai.swipereveallayout.SwipeRevealLayout;
import com.tble.brgo.InfoArticle;
import com.tble.brgo.R;
import android.graphics.Typeface;
import android.widget.Filterable;
import android.widget.Filter;

import org.w3c.dom.Text;

/**
 * Created by Praveen on 8/21/16.
 */
public class StandardCellAdapter extends ArrayAdapter<InfoArticle> implements Filterable {
    public ArrayList<InfoArticle> orig;
    public ArrayList<InfoArticle> Teachers;
    public SwipeRevealLayout swipeV;
    public TextView deleteButton;
    public TextView saveButton;
    public int tableType;
    public displayInterface activity;
    public Context ct;
    public StandardCellAdapter(Context context, ArrayList<InfoArticle> titles, int tableType, displayInterface inter) {
        super(context, 0, titles);
        this.Teachers = titles;
        this.tableType = tableType;
        saveButton = new TextView(context);
        deleteButton = new TextView(context);
        activity = inter;
        ct = context;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // Get the data item for this position
        String title = getItem(position).title;
        String desc = getItem(position).description;
        Holder TagHolder = null;
        TextView Ctitle;
        // Check if an existing view is being reused, otherwise inflate the view
        if (convertView == null) {
            if (tableType == 0) {
                convertView = LayoutInflater.from(getContext()).inflate(R.layout.nclayout, parent, false);
                Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
            }
            else if(tableType == 1){
                convertView = LayoutInflater.from(getContext()).inflate(R.layout.sclayout, parent, false);
                Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
                TagHolder = new Holder();
                swipeV = (SwipeRevealLayout)convertView.findViewById(R.id.scSwipe);
                saveButton = (TextView)convertView.findViewById(R.id.saveButton);
                TagHolder.Save = saveButton;
                TagHolder.Cell = Ctitle;
                convertView.setTag(TagHolder);
            }
            else{
                convertView = LayoutInflater.from(getContext()).inflate(R.layout.tclayout, parent, false);
                Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
                TagHolder = new Holder();
                swipeV = (SwipeRevealLayout)convertView.findViewById(R.id.tcSwipe);
                deleteButton = (TextView) convertView.findViewById(R.id.deleteButton);
                TagHolder.Delete = deleteButton;
                TagHolder.Cell = Ctitle;
                convertView.setTag(TagHolder);
            }
        }
        else {
            TagHolder = (Holder) convertView.getTag();
            Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
        }
        if(tableType == 1) {
            TagHolder.Save.setTag(position);
            TagHolder.Save.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    saveTeacher((int)v.getTag());
                }
            });
            TagHolder.Cell.setTag(position);
            TagHolder.Cell.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    activity.displayWebpage(getItem((int)v.getTag()).description);
                }
            });
        }
        else if(tableType == 2) {
            TagHolder.Delete.setTag(position);
            deleteButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    deleteTeacher((int)v.getTag());
                    if(Teachers.size() == 0)
                        Teachers.add(new InfoArticle("Slide to Save Teachers", "google.com"));
                    notifyDataSetChanged();
                }
            });
            TagHolder.Cell.setTag(position);
            TagHolder.Cell.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    activity.displayWebpage(getItem((int)v.getTag()).description);
                }
            });
        }
        Typeface customFont = Typeface.SERIF;
        Ctitle.setTypeface(customFont);
        Ctitle.setText(title);
        return convertView;
    }
    public Filter getFilter() {
        return new Filter() {

            @Override
            protected FilterResults performFiltering(CharSequence constraint) {
                final FilterResults oReturn = new FilterResults();
                final ArrayList<InfoArticle> results = new ArrayList<InfoArticle>();
                if (orig == null)
                    orig = Teachers;
                if (constraint != null) {
                    if (orig != null && orig.size() > 0) {
                        for (final InfoArticle g : orig) {
                            if (g.title.toLowerCase()
                                    .contains(constraint.toString().toLowerCase())) {
                                results.add(g);
                            }

                        }
                    }
                    oReturn.values = results;
                }
                return oReturn;
            }

            @SuppressWarnings("unchecked")
            @Override
            protected void publishResults(CharSequence constraint,
                                          FilterResults results) {
                Teachers = (ArrayList<InfoArticle>)results.values;
                notifyDataSetChanged();
            }
        };
    }
    @Override
    public void notifyDataSetChanged() {
        super.notifyDataSetChanged();
    }

    public ArrayList<InfoArticle> toIA(ArrayList<String> data){
        ArrayList<InfoArticle> converted = new ArrayList<InfoArticle>();
        for(String a: data)
        {
            converted.add(new InfoArticle(a,""));
        }
        return converted;
    }


    @Override
    public int getCount() {
        return Teachers.size();
    }

    @Override
    public InfoArticle getItem(int position) {
        return Teachers.get(position);
    }

    public void saveTeacher(int position){
        SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
        SharedPreferences.Editor editor = sharedPref.edit();
        Set<String> teach = sharedPref.getStringSet("teachPref", new HashSet<String>());
        teach.add(Teachers.get(position).title);
        Set<String> link = sharedPref.getStringSet("linkPref", new HashSet<String>());
        link.add(Teachers.get(position).description);
        editor.putStringSet("teachPref", teach);
        editor.putStringSet("linkPref", link);
        editor.apply();
        new AlertDialog.Builder(getContext())
                .setTitle("Teacher Saved")
                .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // continue with delete
                    }
                }).setIcon(android.R.drawable.ic_dialog_alert)
                .show();
        swipeV.close(true);
    }
    private void deleteTeacher(int position){
        SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
        SharedPreferences.Editor editor = sharedPref.edit();
        Set<String> teach = sharedPref.getStringSet("teachPref", new HashSet<String>());
        Set<String> link = sharedPref.getStringSet("linkPref", new HashSet<String>());
        teach.remove(Teachers.get(position).title);
        link.remove(Teachers.get(position).description);
        editor.putStringSet("teachPref", teach);
        editor.putStringSet("linkPref", link);
        editor.apply();
        HashSet<String> defv = new HashSet<String>();
        Teachers.remove(position);
        new AlertDialog.Builder(getContext())
                .setTitle("Teacher Deleted")
                .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        // continue with delete
                    }
                }).setIcon(android.R.drawable.ic_dialog_alert)
                .show();
        swipeV.close(false);
    }
    class Holder{
        TextView Delete;
        TextView Save;
        TextView Cell;
    }
}