Unable to add Facebook Event Calendar subscription to Calendar app
For years, I've had access to my Facebook Event Calendar in the Calendar app on my iOS devices. I've also had access to this calendar in other calendar apps, such as Google Calendar and Outlook. I'm referring to the calendar you can access from the full browser version of Facebook by clicking Events under the main menu, then Your Events, and then copying the ical URL from the Add to Calendar button in the upper-right of the window. The URL is in the form https://www.facebook.com/events/ical/upcoming/?uid=123456789&key=AaBbCcDdEeFfGgHh (my personal uid and key are masked here for privacy reasons).
A couple of weeks ago, I noticed that events from my Facebook Event Calendar were no longer showing up in the Calendar app on my iOS devices, even though they still show up correctly in Google Calendar. Perhaps this coincided with the update to iOS version 16.5.1.
I tried removing the Facebook Event Calendar from the Calendar app and then re-adding it, but I was unable to re-add the calendar subscription. In the Settings app, I go to Calendar->Accounts->Add Account->Other->Add Subscribed Calendar, I enter the URL, and I tap Next. Then I encounter the error message, "cannot connect using SSL." If I then proceed with SSL disabled, I get, "unable to verify account information." So I cannot add the calendar subscription anymore. This used to work only a few weeks ago, and the calendar subscription still works in Google Calendar. What changed in the iOS Calendar app to stop this from working suddenly?
iPhone 12 mini, iOS 16