So I am still struggling with this issue. My issue is slightly different than most people in that I am not as much worried about Mac/iOS interoperability but just that when a user launches the next version of my app, they don't get the alert to allow the app to have access to the data.
My shipping Mac app stores it's data in an app group so that my internal extensions can also access the same data. This app group is named group... This has been done for years and works great. It also works fine on Sequoia (for currently shipping version).
However, when I build the app with Xcode 16, I am now getting the alert. The alert happens even before my app delegate is loaded so it appears by just having the app group listed in my entitlements (or info.plist) is causing the alert.
Therefore, even if I wanted to migrate the user's data to a new location, they would still get the alert until all users migrated and I could do a new release removing the entitlement.
To be clear, on Sequoia 15.0.1 and using released Xcode 16, I am still getting this alert when building for the App Store (Test Flight) or direct distribution.
@colink, it sounds like you might have solved this for Test Flight builds but unclear what you did to do this.
Any help on this would be greatly appreciated!!!
//Ray