View with @FetchRequest doesn't update when items added/removed from another device

I thought that if a View had

Code Block 
@FetchRequest(…) private var items: FetchedResults<Item>

and the body contained

Code Block 
ForEach(items) { item in
	…
}

that that would be enough for insertions and deletions to update the view automatically. Is there more that I need to do?

Context

I created a cross-platform app using the "App" template in Xcode 12.4 this morning. The template creates a model with an Item entity, and a main view that renders a list of all items and their creation timestamps.

In both iOS and macOS targets, I enabled CloudKit, created a container, and enabled background notifications. Then I confirmed that if I opened the app from my phone, I could see items created on my Mac, and vice versa.

However, neither device shows changes (insertions or deletions) made on the other device until the app is restarted.

Code Block 
		guard let persistentStoreDescriptions = container.persistentStoreDescriptions.first else {
			fatalError("\(#function): Failed to retrieve a persistent store description.")
		}
		persistentStoreDescriptions.setOption(true as NSNumber,
																					forKey: NSPersistentHistoryTrackingKey)
		persistentStoreDescriptions.setOption(true as NSNumber,
																					forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey)
		
		container.loadPersistentStores(completionHandler: { (storeDescription, error) in ... })
		container.viewContext.automaticallyMergesChangesFromParent = true
		container.viewContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy