The .listStyle(.carousel) code is used in WWDC19 (SwiftUI on watchOS) as well so it must not require Xcode 13. Replacing it with CarouselListStyle() is what worked for me though. I'm using Xcode 12.5.

Maybe this has already been solved or everyone, but this wasn't working for me and it looks like I needed to add mergePolicy and set the automaticallyMergesChangesFromParent on the container's viewContext. Mine looks like this now: container.viewContext.mergePolicy = NSMergeByPropertyStoreTrumpMergePolicy         container.viewContext.automaticallyMergesChangesFromParent = true After removing the app and re-running Xcode the data all synced as expected.