I have already modified the code of your plugin to show the missing meta.
Here is a FRESH WordPress with NOTHING but NOO installed - as you can see NO Class meta is shown using your OWN test page. Very easy to replicate at your end, you don't need my login to see and fix the issue.
https://polinak7.sg-host.com/noo-timetable-class/
Your ntt-class.php code that is responsible for generating the shortcode does NOT have the variable $show_class_meta defined so nothing is being shown. It also does NOT respect "show_info" setting - whether it is selected in shortcode builder as show date and time or added manually to shortcode as show_info='all'
Install your own plugin on your own test WordPress and fix the issues before releasing an update to the public that breaks existing functionality.