Since ~July 10, NSPersistentCloudKitContainer export has failed on every device on my iCloud account; import still works. In CloudKit Console → Logs (Production), the only failing operations are RecordDelete/RecordSave of record type pcs_data (error BAD_REQUEST) in the private com.apple.coredata.cloudkit.zone. No CD* app-record failures; the app schema is fully deployed to Production.
Advanced Data Protection is enabled on the account, so PCS keys are managed end-to-end on-device. This looks like a wedged PCS key state rather than an app/schema problem.
Tried with no effect: toggling ADP off/on, toggling iCloud Keychain, multiple reboots, app reinstall, extended foreground on Wi-Fi. Still failing after updating from iOS 27 Seed 3 to beta 4.
Is there a way to get the account's Protected Cloud Storage key state reset so export can resume? Happy to share the Feedback number and sysdiagnoses privately with an Apple engineer.