JQuery / WooCommerce Bookings - Wrong dimensions for hidden elements

Question

I use WooCommerce Bookings and just placed the Calendar View from the top into one of the WooCommerce Tabs. As this tab has display:none; when the visitor hits the website, the jQuery plugin does not calculate the dimensions of the days correctly.

I can see this code in the JavaScript file, but how I can manage that the sizes are set correctly from the beginning?

$('.block-picker a').each(function() {
    var width  = $(this).width();
    var height = $(this).height();
    if ( width > max_width ) {
        max_width = width;
    }
    if ( height > max_height ) {
        max_height = height;
    }
});

$('.block-picker a').width( max_width );
$('.block-picker a').height( max_height );

I even tried to execute this code when somebody presses on the tab button, but this does not change anything.

Would be great if somebody can help.

Thanks!