The “Prevent cross-site tracking” preference has been in Safari since at least iOS 11 and High Sierra (2017?). No idea if it is enabled by default but I have no recollection of ever having to turn it on manually on any device.
Until recently (perhaps the 10.15.4 update?) I’ve never seen it cause any problems. Lately, though, I’ve been running into a few issues where turning it off resolves the problem. Two examples:
- Using Office 365 Outlook’s web interface with the Zoom Outlook plugin: when x-site tracking prevention is checked, the plugin prompts you to sign into Zoom but never really authenticates and you can’t use the plugin to add a Zoom meeting to an Outlook appointment. Unchecking the x-site preference (which disables Safari’s blocking of cross-site tracking), allows the Zoom plugin to work as usual.
- Tableau’s e-learning site uses single sign on and while it allows you to sign on with the x-site preference checked, it will not show content. Again, unchecking this preference allows the site to function.
Both worked regularly in Safari up until a few weeks ago, although with everything going on, I can’t be sure of a certain date or 100% tie it to the macOS 10.15.4 update.
According to Apple’s 10.15.4 release notes the only change to Safari seems unrelated:
- Content Blocker extensions delivered with Mac Catalyst apps are now available for use in Safari. (43646265)
I only use these sites on macOS, so I’m not sure if the same occurs in iOS/iPadOS.
If you know of any, I’d love to be able to point these vendors to Apple’s guidance on how to prevent being blocked by this feature in Safari.
Because I completely understand the need for this feature I don’t want to just leave it off for all browsing. So, as a (hopefully temporary) workaround, I have created a Keyboard Maestro shortcut (forgot how annoying it is to try to automate/script Preferences for macOS app) to toggle the preference when I visit one of these sites. If anyone’s interested, I will post it.