Issues with [agenda] shortcode

Hi there,
after adding the [agenda] short code in a page, not all sessions are displayed (only the keynotes, non-sessions e.g. breaks and the special tracks are visible) – the correct time-slot is displayed though, but the assigned “normal” session (with title & description) is missing….

Did anyone encounter the same issue with the agenda short code and how I can resolve this? Thanks for your help!

https://ww.wp.xz.cn/plugins/conferencer/