I'm experiencing exactly the same issue since upgrading to iOS 26.4 with the same code, and it's also blocking Live Activities updates.
I'm also having issues on tvOS 26.4, which uses CKSyncEngine.
I'm experiencing exactly the same issue since upgrading to iOS 26.4 with the same code, and it's also blocking Live Activities updates.
I'm also having issues on tvOS 26.4, which uses CKSyncEngine.