Bootstrap模态框关闭后无法重新打开的问题求助

我碰到个头疼的问题：Bootstrap模态框第一次打开、关闭都毫无问题，但第二次点击打开按钮想重新打开时，它完全没反应，死活打不开。有没有大佬能帮我分析下原因，给个解决办法？

这个模态框是用来添加新机构数据的，第一次操作一切正常，就是关闭后再点打开按钮就失效了，以下是我的相关代码：

HTML 代码 #

<button id="BtnAddDisplay" class="btn custom-button col-12" type="button" onclick="INSERT_REQUEST_DEGREE_EQUATION_MODAL(); return false;">
        ارسال الى جهه جديده
    </button>
<div class="modal fade" id="INSERT_REQUEST_DEGREE_EQUATIONModal" tabindex="-1" aria-labelledby="INSERT_REQUEST_DEGREE_EQUATIONModalLabel" aria-hidden="true">
  <div class="modal-dialog custom-modal-dialog">
    <div class="modal-content">
      <div class="modal-header btn-dark text-center w-100">
        <h5 class="modal-title text-white w-100" id="INSERT_REQUEST_DEGREE_EQUATIONModalLabel">اضافه جهه جديده</h5>
        <button type="button" class="close text-white" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body">
               <div class="row">
                    <div class="col-12">
                        <div class="card">
                            <div class="card-header">
                                <h6 class="card-subtitle line-on-side text-muted text-center font-small-4 pt-1">دراسة مواد للشهادة ذاتها بجامعات أخرى</h6>
                            </div>
                            <div class="card-body">
          
                                <div id="dvTransfersInputs" class="row transfers">
                                    <div class="col-12 col-md-4">
                                        <div class="form-group">
                                            <label class="control-label">
                                                <asp:Literal Text="<%$ Resources:Resource1, P_COUNTRY_ID %>" runat="server" />
                                            </label>
                                              <asp:DropDownList ID='ddlP_COUNTRY_ID_equation' runat='server' 
                                    CssClass='chosen-select chosen-rtl form-control' 
                                    data-placeholder="<%$ Resources:Resource1, ddl-placeholder %>" 
                                    ClientIDMode='Static' 
                                    onchange="handleDropdownChange_country(this)">
                                    <asp:ListItem Value="" Text="" Selected="True"></asp:ListItem>
                                </asp:DropDownList>
                                        </div>
                                    </div>
                                    <div class="col-12 col-md-4">
                                        <div class="form-group">
                                            <label class="control-label">
                                                <asp:Literal Text="<%$ Resources:Resource1, P_UNIVERSITY_ID %>" runat="server" />
                                            </label>
                                            <asp:DropDownList ID='ddlP_UNIVERSITY_ID_equation' runat='server' CssClass='chosen-select chosen-rtl form-control' data-placeholder="<%$ Resources:Resource1, ddl-placeholder %>" ClientIDMode='Static'  onchange="handleDropdownChange_university(this)">
                                                <asp:ListItem Value="" Text="" Selected="True"></asp:ListItem>
                                            </asp:DropDownList>
                                        </div>
                                    </div>
                                    <div class="col-12 col-md-4">
                                        <div class="form-group">
                                            <label class="control-label">
                                                <asp:Literal Text="<%$ Resources:Resource1, P_OFFICE_ID %>" runat="server" />
                                            </label>
                                            <asp:DropDownList ID='ddlP_OFFICE_ID_equation' runat='server' CssClass='chosen-select chosen-rtl form-control' data-placeholder="<%$ Resources:Resource1, ddl-placeholder %>" ClientIDMode='Static' onchange="handleDropdownChange_office(this)">
                                                <asp:ListItem Value="" Text="" Selected="True"></asp:ListItem>
                                            </asp:DropDownList>
                                        </div>
                                    </div>
                          
                                </div>
                            </div>
                 
                        </div>

                    </div>
                </div>
      </div>
      <div class="modal-footer justify-content-center">
       <button type="button" onclick="INSERT_UPD_E_TRANS_REQUEST_DEGREE_EQUATION_TRANSFARED()" class="btn btn-success">اضافه</button>
       <button type="button" class="btn btn-danger" data-dismiss="modal">الغاء</button>
      </div>
    </div>
  </div>
</div>

打开模态框的JS代码 #

function INSERT_REQUEST_DEGREE_EQUATION_MODAL() {
    debugger;
    //$('.chosen-select').chosen({
    //    no_results_text: "No results matched",
    //    width: "100%"
    //});
    // check values of country
    $('#ddlP_OFFICE_ID_equation').val('').trigger('chosen:updated');
    $('#ddlP_UNIVERSITY_ID_equation').val('').trigger('chosen:updated');
    $('#ddlP_COUNTRY_ID_equation').val('').trigger('chosen:updated');
    var hiddenCountryValue = $('#HiddenCountry').val();
    var countries = JSON.parse(hiddenCountryValue);

    // Clear the dropdown and add a default empty option
    var $ddlCountry = $('#ddlP_COUNTRY_ID_equation');
    $ddlCountry.empty();
    $ddlCountry.append($('<option>', {
        value: '',
        text: 'اختر من القائمه'
    }));

    // Populate the dropdown with the JSON data
    $.each(countries, function (index, country) {
        $ddlCountry.append($('<option>', {
            value: country.COUNTRY_ID,
            text: country.COUNTRY_NAME
        }));
    });

    // Set the selected index to 0 (default option)
    $ddlCountry.prop('selectedIndex', 0);

    // Trigger the chosen update if you are using the chosen plugin
    $ddlCountry.trigger('chosen:updated');

    //========== Check university
    // Get the JSON data from the hidden field for Universities
    var hiddenUniversityValue = $('#HiddenUniversity').val();
    var universities = JSON.parse(hiddenUniversityValue);

    // Clear the University dropdown and add a default empty option
    var $ddlUniversity = $('#ddlP_UNIVERSITY_ID_equation');
    $ddlUniversity.empty();
    $ddlUniversity.append($('<option>', {
        value: '',
        text: 'اختر من القائمه'
    }));

    // Populate the University dropdown with the JSON data
    $.each(universities, function (index, university) {
        $ddlUniversity.append($('<option>', {
            value: university.UNIVERSITY_ID,
            text: university.UNIVERSITY_DESC
        }));
    });

    // Set the selected index to 0 (default option)
    $ddlUniversity.prop('selectedIndex', 0);

    // Trigger the chosen update for University dropdown
    $ddlUniversity.trigger('chosen:updated');

    //=========== Check office
    var hiddenOfficeValue = $('#HiddenOffice').val();
    var offices = JSON.parse(hiddenOfficeValue);

    // Clear the Office dropdown and add a default empty option
    var $ddlOffice = $('#ddlP_OFFICE_ID_equation');
    $ddlOffice.empty();
    $ddlOffice.append($('<option>', {
        value: '',
        text: 'اختر من القائمه'
    }));

    // Populate the Office dropdown with the JSON data
    $.each(offices, function (index, office) {
        $ddlOffice.append($('<option>', {
            value: office.OFFICE_ID,
            text: office.OFFICE_NAME
        }));
    });

    // Set the selected index to 0 (default option)
    $ddlOffice.prop('selectedIndex', 0);

    // Trigger the chosen update for Office dropdown
    $ddlOffice.trigger('chosen:updated');

    //============
    $('#INSERT_REQUEST_DEGREE_EQUATIONModal').find('input:text, select').val('').trigger('chosen:updated');

    // Optionally, if you are using other plugins or components, reset their states here

    // Show the modal
    $('#INSERT_REQUEST_DEGREE_EQUATIONModal').modal('show').on('hidden.bs.modal', function () {
        // Perform any clean-up if necessary when the modal is hidden
        // Reset dropdowns or other inputs here if needed
        populateDropdown($('#ddlP_COUNTRY_ID_equation'), countries, 'اختر من القائمه');
        populateDropdown($('#ddlP_UNIVERSITY_ID_equation'), universities, 'اختر من القائمه');
        populateDropd
    });
}

备注：内容来源于stack exchange，提问作者Figo Eldakhlawy