Пытаюсь освоить autocompletetextview в Android. Написал свой адаптер, который должен выводить имя объекта. Работает, но не поддерживает русский язык

Помогите, чтобы адаптер распознавал русские символы. Код модели:

public class CategoryModel {
private String id;
private String name;
private AuthorizationclientModel authorizationclientModel;


public CategoryModel() {
}

public CategoryModel(String id, String name, AuthorizationclientModel authorizationclientModel) {
    this.id = id;
    this.name = name;
    this.authorizationclientModel = authorizationclientModel;
}

public String getId() {
    return id;
}

public void setId(String id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public AuthorizationclientModel getAuthorizationclientModel() {
    return authorizationclientModel;
}

public void setAuthorizationclientModel(AuthorizationclientModel authorizationclientModel) {
    this.authorizationclientModel = authorizationclientModel;
}

@Override
public String toString() {
    return "ProductCategoryModel{" +
            "id='" + id + '\'' +
            ", name='" + name + '\'' +
            ", authorizationclientModel=" + authorizationclientModel +
            '}';
}
}

Код адаптера:

public class CategoryNameAdapter extends ArrayAdapter<CategoryModel> {
private List<CategoryModel> categoryModelsFull;


public CategoryNameAdapter(@NonNull Context context, @NonNull List<CategoryModel> categoryModelList) {
    super(context, 0, categoryModelList);
    categoryModelsFull = new ArrayList<>(categoryModelList);
}

@NonNull
@Override
public Filter getFilter() {
    return categoryFilter;
}

@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
    if (convertView == null) {
        convertView = LayoutInflater.from(getContext()).inflate(
                R.layout.name_category, parent, false
        );
    }
    TextView textViewName = convertView.findViewById(R.id.name_category_adapter);
    CategoryModel categoryModel = getItem(position);
    if (categoryModel != null) {
        textViewName.setText(categoryModel.getName());
    }
    return convertView;
}

private Filter categoryFilter = new Filter() {
    @Override
    protected FilterResults performFiltering(CharSequence constraint) {
        FilterResults results = new FilterResults();
        List<CategoryModel>suggestions = new ArrayList<>();
        if (constraint == null || constraint.length() == 0) {
            suggestions.addAll(categoryModelsFull);
        } else {
            String filterPattern = constraint.toString().toLowerCase().trim();
            for (CategoryModel item : categoryModelsFull) {
                if (item.getName().toLowerCase().contains(filterPattern)) {
                    suggestions.add(item);
                }
            }
        }
        results.values = suggestions;
        results.count = suggestions.size();
        return results;
    }

    @Override
    protected void publishResults(CharSequence constraint, FilterResults results) {
        clear();
        addAll((List) results.values);
        notifyDataSetChanged();
    }

    @Override
    public CharSequence convertResultToString(Object resultValue) {
        return ((CategoryModel) resultValue).getName();
    }
};
}

Функция, которая парсит json:

public void loadCategory(){
    StringRequest stringRequest = new StringRequest(Request.Method.GET, URLCategory,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    try {
                        JSONArray jsonArray = new JSONArray(response);
                        for(int i =0;i<jsonArray.length();i++) {
                            JSONObject categoryObject = jsonArray.getJSONObject(i);
                            JSONObject authorizationClientObject = categoryObject.getJSONObject("authorizationClientCategory");


                            CategoryModel categoryModel = new CategoryModel();
                            AuthorizationclientModel authorizationclientModel = new AuthorizationclientModel();

                            authorizationclientModel.setId(authorizationClientObject.getString("id"));
                            authorizationclientModel.setUsername(authorizationClientObject.getString("username"));
                            authorizationclientModel.setPassword(authorizationClientObject.getString("password"));

                            categoryModel.setId(categoryObject.getString("id").toString());
                            categoryModel.setName(categoryObject.getString("name").toString());
                            categoryModel.setAuthorizationclientModel(authorizationclientModel);

                            categoryModelList.add(categoryModel);
                        }
                        autoCompleteTextViewCategory.setThreshold(1);
                        categoryAdapter = new CategoryNameAdapter(NewPurchases.this,categoryModelList);
                        autoCompleteTextViewCategory.setAdapter(categoryAdapter);
                        autoCompleteTextViewCategory.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                            @Override
                            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                                CategoryModel categoryModel = (CategoryModel) parent.getItemAtPosition(position);
                                ID_Category=categoryModel.getId();
                                loadProduct();
                            }
                        });
                    }
                    catch (JSONException e){
                        e.printStackTrace();
                    }
                }


            }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            Toast.makeText(NewPurchases.this,"Server Error",Toast.LENGTH_SHORT).show();
        }
    }
    );
    RequestQueue queue = Volley.newRequestQueue(this);
    queue.add(stringRequest);
}