Filed values changes unexpectedly using checkbox

I have multiple checkbox and their field name but i dont know where i have done wrong the name of the field changes i am unable to find out where is the problem.

Here my screen shot when checkbox values were fine:here is fine fields working good

And this here is screen shot there is multiple questions marks like ???? and these becoming annoying this fields value are with ???? there should not any question marks in this field

And my form where these checkboxes value are:

                  <form id="preferences_form" role="form" method="POST" novalidate action="" class="mujucet-registration">
                            
                            <h5>Nastavení zpráv</h5>
                            <div class="row">
                                <div class="col-md-4">
                                    <div class="checkbox">
                                        <label  for="ch1">
                                            <input type="checkbox" name="monthly" value="1" id="ch1"><span class="cr"><i class="cr-icon fa fa-check"></i></span>Mesícní výpisy
                                        </label>
                                    </div>
                                </div>
                                <div class="col-md-4">
                                    <div class="checkbox">
                                        <label >
                                            <input type="checkbox" name="weekly" value="1"><span class="cr"><i class="cr-icon fa fa-check"></i></span>Týdenní prehled
                                        </label>
                                    </div>
                                </div>
                                <div class="col-md-4">
                                    <div class="checkbox">
                                        <label>
                                            <input type="checkbox" name="tax_reviews" value="1"><span class="cr"><i class="cr-icon fa fa-check"></i></span>Danové výpisy
                                        </label>
                                    </div>
                                </div>

                                <div class="col-md-4">
                                    <div class="checkbox">
                                        <label>
                                            <input type="checkbox" name="quarterly" value="1"><span class="cr"><i class="cr-icon fa fa-check"></i></span>Ctvrtletní výpisy
                                        </label>
                                    </div>
                                </div>
                                <div class="col-md-4">
                                    <div class="checkbox">
                                        <label>
                                            <input type="checkbox" name="annually" value="1"><span class="cr"><i class="cr-icon fa fa-check"></i></span>Rocní výpisy
                                        </label>
                                    </div>
                                </div>
                                <div class="col-md-4">
                                    <div class="checkbox">
                                        <label>
                                            <input type="checkbox" name="newsletter" value="1"><span class="cr"><i class="cr-icon fa fa-check"></i></span>Novinky
                                        </label>
                                    </div>
                                </div>

                                <div class="col-md-12">
                                    <div class="checkbox">
                                        <label class="border">
                                            <input type="checkbox" name="direct_mail_reviews" value="1"><span class="cr"><i class="cr-icon fa fa-check"></i></span> Chci výpisy zasílat také Poštou <span class="light">20 kc za výpis</span>
                                        </label>
                                    </div>
                                </div>

                            </div><h5>Kontaktní preference</h5>
                            <div class="row">
                                <div class="col-md-4">
                                    <div class="checkbox">
                                        <label>
                                            <input type="checkbox" name="email" value="1"><span class="cr"><i class="cr-icon fa fa-check"></i></span>Email
                                        </label>
                                    </div>
                                </div>
                                <div class="col-md-4">
                                    <div class="checkbox">
                                        <label>
                                            <input type="checkbox" name="sms" value="1"><span class="cr"><i class="cr-icon fa fa-check"></i></span>SMS
                                        </label>
                                    </div>
                                </div>
                            </div>
                        </form>                    </div>

I dont how my checkboxes value goes weird here your help will be highly appreciated!