I have an HTML page which embeds my Google Calendar. (My school uses Google for Education.) That Google Calendar is set to show event details to members of my school. Using all other browsers that I have tried, this works fine: If a user is signed in to Google and accesses the HTML page, they see the embedded calendar with event details. However, if anyone (including myself) access the page through Firefox, the embedded calendar is shown with the events labeled only as "busy."

I have not tested every possible combination, but I should at least be able to view my own calendar. What could be causing this? I can try modifications either in the Firefox I'm using to view the page, or modifications to the HTML page itself.