This feature is listed as "experimental" in Google Chrome, but for some reason is enabled by default. We've seen this cause a disruption between Zendesk and a third-party integration here, and I saw another user on the Mac Admins Slack say it's causing an issue for Cloudflare Zero Trust in his environment, so I wanted to share the fix in case it's useful for anyone else.
I resolved this by deploying a PLIST via configuration profile with the following key/value pair:
<key>DefaultThirdPartyStoragePartitioningSetting</key>
<integer>2</integer>
When you do this, it'll look like nothing changed. The flag is still set to "Default" just as it was before. The difference is that what the default is has changed under the hood. You can verify that your profile deployed successfully by typing chrome://policy in the Chrome search bar. This will show you a list of all of the Chrome policies that you're managing. Make sure you quit Chrome and re-open it before checking. Finally, check whatever website was previously broken by this experimental feature and verify that it's working.
Because Microsoft Edge is a Chromium browser, it also has this experimental feature enabled by default, and the key/value pair is exactly the same.
The application domain for Chrome is com.google.Chrome and for Edge it's com.microsoft.Edge.
Although this wasn't strictly necessary, this also led me down a path to writing my own JSON schema for Chrome and Edge, and that was a fun learning process!
If anyone has any questions, let me know!
