Error: “Unable to load calendar data”

Good morning! Calendar view is working for users logged into the site, but not for those who are unauthenticated. I tried the recommendations in a related past forum discussion, but all that has done is made the page show that it is “loading…” rather than displaying the error. (https://ww.wp.xz.cn/support/topic/unable-to-load-calendar-data/?view=all#post-18933764)

Any recommendations?

The page I need help with: [log in to see the link]