I'm using the shortcode in a template file, it looks like this
echo do_shortcode('[events_list_grouped mode="daily" date_format="l" format_header="<ul>" format_footer="</ul>"]<li>#_24HSTARTTIME - #_EVENTLINK </li> [/events_list_grouped]');
This code returns all the events but also adds some file attachment and other post types than events. It even adds different start time to items that have no time set to it (not event post types);
There is really no more information I can give sins I'm not sure how to debug this plugin.