We had an issue with IDrive Online Backup which has started discussing on the Developer forum at https://developer.apple.com/forums/thread/756904 and as suggested raised a technical support ticket Case-ID: 7747625. At last the old legacy bundle ID prefix changed to to the new Team ID prefix. As a result  one-time loss of keychain data occurs, however we requested and were granted an additional keychain capability that allowed access to keychain data stored under the old legacy prefix, even after transitioning to the new Team ID prefix. We are currently facing a similar challenge with our other application, IBackup. As with the earlier case, we had a mismatch between the App ID prefix and the Team ID, which we resolved by updating the prefix to match the Team ID. Again now encountered a blocker with Keychain data recovery. We have already requested the additional Keychain capability that would allow access to keychain data stored under the old legacy prefix, even after transitioning to the new Team ID prefix. Unfortunately, the team responsible for this has some uncertainty about the process. Please review the details under case 102398017929 and extend this capability to our application to ensure a seamless user experience.