I just recently received disturbing calendar spam... How is that deleted and then protected from such nonsense??? I was not even aware calendars had invites at all but if I can delete those spam material then I will delete the calendar completely...
You have a rogue calendar that was installed when you accepted what you thought was a “free” offer on a website or in an app. See the post from Axel F. in this linked thread to remove it—>Spam in my calendar - Apple Community
See this support guide at section "Unsubscribe from other calendars":--> How to unsubscribe from calendars on your iPhone
Regards
Giulio
Calendar Spam
