DataTable column header disappeared after sorting

 var table3 = $("#tblFacultySave").DataTable({
          @* 68 - CR20210212 - #68 - lakshmi - 20210217 - 'Freeze table header' *@
            "scrollY": "700px",
            "scrollX": true,
            "sorting": false,
            "scrollCollapse": true,
            "deferRender": true,
            "order": [[2, "asc"]],
            "columnDefs": [
                { "type": "numeric-comma", targets: "_all" }],
            "pageLength": @totalRecordsperPage,
        })




                        $("#tblFacultySave").append('<tr><td><input type="text" name="StaffID' + resultData[i].FACID + '"  id="StaffID' +
                            resultData[i].FACID + '" readonly value="' + STAFFIDNULL + '"/></td><td><input type="text" name="FullName' +
                            resultData[i].FACID + '"  id="FullName' + resultData[i].FACID + '" readonly value="' +
                            NAMENULL + '"/></td><td><input type="text" name="DepartmentPrimary' + resultData[i].FACID + '"  id="DepartmentPrimary' +
                            resultData[i].FACID + '" readonly value="' + DUKEPRIMARRYDEPARTMENTDB + '"/></td><td><input type="text" name="primaryinstitution' +
                            resultData[i].FACID + '"  id="primaryinstitution' + resultData[i].FACID + '" readonly value="' +
                            PRIMARYINSTITUTIONNULL + '"/></td><td><input type="text" name="primaryempdepartment' + resultData[i].FACID + '"  id="primaryempdepartment' +
                            resultData[i].FACID + '" readonly value="' + PRIMARYEMPDEPARTMENTNULL + '"/></td><td><input type="text" name="CurrentTitle' +
                            resultData[i].FACID + '"  id="CurrentTitle' + resultData[i].FACID + '" readonly value="' +
                            CURRENTTITLENULL + '"/></td><td><input type="text" name="CurrentTrack' + resultData[i].FACID + '"  id="CurrentTrack' +
                            resultData[i].FACID + '" readonly value="' + CURRENTTRACKNULL + '"/></td><td><input type="text" name="CurrentTenure' +
                            resultData[i].FACID + '"  id="CurrentTenure' + resultData[i].FACID + '" readonly value="' +
                            CURRENTTENURENULL + '"/></td><td><input type="button" value="Remove"  class="removefaculty"/><input type="hidden" name="Facid' +
                            resultData[i].FACID + '"  id="Facid' + resultData[i].FACID + '" readonly value="' + resultData[i].FACID + '"</td></tr>');