Month and year in datepickers dropdown are not refreshing on MM-yy format

In date picker if your textbox type is month and year only,

You select a date like April 2018 and focus out of textbox

again focus back in textbox and open datepicker and you will find that it started with first value in change year and month dropdowns

let me know if further inputs are required

   $(function () {
        $('.date-picker').datepicker({
            changeMonth: true,
            changeYear: true,
            showButtonPanel: true,
            dateFormat: 'MM yy',
            onClose: function (dateText, inst) {
                var month = $("#ui-datepicker-div .ui-datepicker-month :selected").val();
                var year = $("#ui-datepicker-div .ui-datepicker-year :selected").val();
                $(this).datepicker('setDate', new Date(year, month, 1));
            }
        });
    });