autoSelectFirstOption doesn't do anything

[DonatoDeluxe]

i've an asp.net 7.0 MVC project where i create a select as following:
<select id="slct-employeeIDs" name="EmployeeIDs" asp-items="ViewBag.EmployeeListData" required></select>

then later i initialize VirtualSelect like this:

$(document).ready(function () {
    // https://www.cssscript.com/select-box-virtual-scroll/
    var vs = VirtualSelect.init({
        ele: '#slct-employeeIDs',
        multiple: true,
        search: true,
        placeholder: '-Bitte wählen-',
        // disable select all
        disableSelectAll: true,
        // autofocus dropdown on load
        autofocus: true,
        // select first option by default on load
        autoSelectFirstOption: false,
    });
});

but it does still select the first option on every page reload.
i also tried to use selectedValue: "@ViewBag.EmployeeIDs".split(',') but again without any success...

i'm using version Virtual Select v1.0.41

thank you for your help in advance.