automatic trashed after 24 hours doesn't work

I’ll double check if this is working for me. The option sets up a cron job which is run every 24 hours (kind of – see how WP Cron works).

Every 24 hours it checks for expired events. Expired events are those whose last occurrence finished at least 24 hours ago. So for recurring events, they won’t be deleted until at least 24 hours after the last occurrence finishes.