Hi,

You could achieve this via a custom hook.

Open your theme or child-theme functions.php file and at the bottom place:

/**
 * Disable accordeon animation on agenda list
 */
add_action('wp_footer', function () {
    if (!wp_script_is('stec-js')) {
        return '';
    }
    ?>
    <script type="text/javascript">
        (function($) {
            $(function() {
                if (typeof $.stecExtend !== 'function') {
                    return;
                }
                $.stecExtend(function(m) {
                    m.helper.animate.agenda.fillList = function($container, callback, instant) {
                        var $events = $container
                            .find('.stec-layout-agenda-events-all')
                            .find('.stec-layout-event-preview')
                            .not('.stec-layout-event-preview-animate-complete');
                        $events.addClass('stec-layout-event-preview-animate-complete');
                        if (typeof callback === 'function') {
                            callback();
                        }
                    }
                });
            });
        })(jQuery);
    </script>
<?php
});

I think this is happening because of this error:

It seems like the Moment library is being deferred on your website:

Please ensure that you are not deferring this script, as it causes issues with your website's functionality. It's possible that this setting was enabled by a plugin you are using for optimization purposes.