Details in "month View" do not open

Hallo,

My Problem is reproducible in all my Browsers (Firefox 43.0.4, Safari 8.0.7, IE 11.0.27)

Situation:
The Website shows the month View. Normaly the Details open in a layer above the calendar. (mc-grid.js is used – Its unchanged an printed on the end of this post)
I use the following String in the WordPress backend to give out the calendar: [my_calendar id=”my-calendar” above=”nav”]
The

Problem:
When I clicks on an event the site scrolls a bit up.

Workaround:
The visitor have to change the month. From this up it works till the next reload.

Used mc-grid.js

(function ($) {
    'use strict';
    $(function () {
        $(".calendar-event").children().not(".event-title").hide();
        $(document).on("click", ".calendar-event .event-title",
            function (e) {
                e.preventDefault(); // remove line if you are using a link in the event title
				var current_date = $(this).parent().children();
                $(this).parent().children().not(".event-title").toggle().attr("tabindex", "-1");
				$(this).parent().focus();
				$(".calendar-event").children().not(".event-title").not( current_date ).hide();
            });
        $(document).on("click", ".calendar-event .close",
            function (e) {
                e.preventDefault();
                $(this).closest(".vevent").find(".event-title a").focus();
                $(this).closest("div.details").toggle();
            });
    });
}(jQuery));

https://wordpress.org/plugins/my-calendar/