Facebook Events no longer sync with iCal Calendar

Suddenly my Mac Calendar isn't syncing Facebook Events or Birthdays—there is a warning sign by the those calendars—"Your calendar couldn’t be refreshed"—with the old link. Oddly, those calendars don't show any warnings on my iOS devices—but they're not refreshing and have no current data.

Unfortunately, past advice on these forums no longer applies, as there is no link on the Facebook Events page to add to calendars.

This is the current Facebook help page for the topic:

https://www.facebook.com/help/152652248136178

It says nothing about adding to a Mac—and, worse, appears that it's only possible to export a single Event from iOS at a time.

Are the days of syncing Events and Calendars from Facebook over?

Thanks in advance!