does not update list after resetting and inserting new ...

Hi everyone, after emptying and inserting new options, there are no changes to the video. The code used is the following:

<form asp-controller="DeviceInventoryDataView" asp-action="AppleDeviceDistribution" method="post"><div class="container"><div class="row"><br /></div><div class="row"><div class="col-md-1"><input class="btn btn-info" type="submit" name="dataviewmenu" value="DataView"></div><div class="col-md-1"><input class="btn btn-info" type="submit" name="inventorymenu" value="Home DI"></div><div class="col-md-2"></div><div class="col-md-1"><select id="year" name="year" class="selectpicker" data-width="auto" onchange="getMonthsList()">
                    @{
                        int yId = 1;
                    }
                    @foreach (Dictionary<string, object> year in ViewData["Years"] as List<Dictionary<string, object>>)
                    {
                        if (Convert.ToInt32(year["Year"]) == Convert.ToInt32(ViewData["SelectedYear"])){<option id="@yId" value="@Convert.ToInt32(year["Year"])" selected>@Convert.ToInt32(year["Year"])</option>
                        }
                        else{<option id="@yId" value="@Convert.ToInt32(year["Year"])">@Convert.ToInt32(year["Year"])</option>
                        }
                        yId++;
                    }</select></div><div class="col-md-1" style="text-align:center"><select id="month" name="month" class="selectpicker" data-width="auto" onchange="getDaysList()">
                    @{
                        int mId = 1;
                    }
                    @foreach (Dictionary<string, object> month in ViewData["Months"] as List<Dictionary<string, object>>)
                    {
                        if (Convert.ToString(month["MonthNumber"]) == Convert.ToString(ViewData["SelectedMonthNumber"]))
                        {<option id="@mId" value="@Convert.ToString(month["MonthNumber"])" selected>@Convert.ToString(month["MonthName"])</option>
                        }
                        else
                        {<option id="@mId" value="@Convert.ToString(month["MonthNumber"])">@Convert.ToString(month["MonthName"])</option>
                        }
                        mId++;
                    }</select></div><div class="col-md-1" id="divDay"><select id="day" name="day" class="selectpicker" data-width="auto">
                    @{
                        int dId = 1;
                    }
                    @foreach (Dictionary<string, object> day in ViewData["Days"] as List<Dictionary<string, object>>)
                    {
                        if (Convert.ToString(day["Day"]) == Convert.ToString(ViewData["SelectedDay"]))
                        {<option id="@dId" value="@Convert.ToString(day["Day"])" selected>@Convert.ToString(day["Day"])</option>
                        }
                        else
                        {<option id="@dId" value="@Convert.ToString(day["Day"])">@Convert.ToString(day["Day"])</option>
                        }
                        dId++;
                    }</select></div><div class="col-md-1" style="text-align:right"><input class="btn btn-info" type="submit" name="refresh" value="Refresh"></div><div class="col-md-3">&nbsp;</div><div class="col-md-1"><a href="@Convert.ToString(ViewData["AppleDeviceDistributionExcelPath"])" target="_blank" class="btn btn-success" role="button">Excel Format</a></div></div></div></form><script type="text/javascript">

function getDaysList() {
        var selectedYear = $("#year").val();
        var selectedMonth = $("#month").val();$.ajax({
            type: 'GET',
            dataType: 'json',
            contentType: 'application/json',
            url: '@Url.Action("GetDays", "AjaxDatabaseManager")',
            data: {
                importTable: 'ImportKeys', selectedMonthValue: JSON.stringify(selectedMonth), selectedYearValue: JSON.stringify(selectedYear)
            },
            success: function (result) {
                var optionNumber = 1;

                var resultObj = result; //JSON.parse(result);

                $("#day").empty(); // remove old options
                //$("#day").append("<option id=\"pleaseselectday\" value=\"pleaseSelect\" selected)>Please Select</option>");$.each(resultObj, function (key, val) {$("#day").append("<option id=\"option" + optionNumber + "day\" value=\"" + val + "\" " + (optionNumber == 1 ? "selected" : "") + ">" + val + "</option>");$("#day").trigger("chosen:updated");
                    optionNumber++;
                    alert("Sto facendo append di " + "<option id=\"option" + optionNumber + "day\" value=\"" + val + "\" " + (optionNumber == 1 ? "selected" : "") + ">" + val + "</option>");
                    alert("Il valore selezionato di day è: " + $("#day").val());
                });
            }
        });
    }</script>

This code is within a cshtml file. Basically when I change the value a month I want to reload the day <select>. The problem is only video refresh because the values I expect are correct, in fact when I post the data are transferred correctly.