Firefox developer here! I've filed a bug for this: https://bugzilla.mozilla.org/show_bug.cgi?id=1770433
When you run into issues like these you can disable Enhanced Tracking Protection via the shield icon in the address bar. This will only disable protections for that specific site. Here is how it works: https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-deskto...