I have since upgraded to MacOS 15.0.1 & iOS 18.0.1 I did and had the same issue. Here are the steps I took. I downloaded the app. Ran the app in Xcode on my iPhone 13 running iOS 18.0.1. The app runs and immediately errors are thrown in the console. I tapped the plus button and receive this error: <0x134159cc0> Gesture: System gesture gate timed out. After I fill out the form, and tap done, this error is thrown: error: the replacement path doesn't exist: "/var/folders/qv/m7sk8kcd3713j3l4bg8wt1lw0000gn/T/swift-generated-sources/@_swiftmacro_11SampleTrips12TripListViewV5trips5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/qv/m7sk8kcd3713j3l4bg8wt1lw0000gn/T/swift-generated-sources/@_swiftmacro_11SampleTrips12TripListViewV5trips5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/qv/m7sk8kcd3713j3l4bg8wt1lw0000gn/T/swift-generated-sources/@_swiftmacro_11SampleTrips12TripListViewV5trips5QueryfMa.swift" The trip populates to the list view and all seems fine. I can edit the view by tapping on it. I changed the date and when returning to the list view, it shows the update. I can add trips. I added one more and it populates just fine. At some point I did receive these errors: CoreSVG has logged an error. Set environment variabe "CORESVG_VERBOSE" to learn more. -[RTIInputSystemClient remoteTextInputSessionWithID:performInputOperation:] perform input operation requires a valid sessionID. inputModality = Keyboard, inputOperation = , customInfoType = UIEmojiSearchOperations I stop the app with the stop button in Xcode. I launch the app from Xcode again. The data is gone. I stop the app with the stop button in Xcode. I launch the app from Xcode. I add new data and receive the same error about the replacement path doesn't exist... I stop the app with the stop button in Xcode. This time when I run the app, the data persists. This represents the first time I have seen data persist. I have seen the data persist now over multiple starts with Xcode and starting the app on the device. It appears to have corrected itself. I decided to check the sample app that appears when you select SwiftData as your storage option in a new project. It still behaves the same. I press the play button in Xcode. The app is loaded onto the phone wirelessly. It runs and I immediately get the replacement path error. error: the replacement path doesn't exist: "/var/folders/qv/m7sk8kcd3713j3l4bg8wt1lw0000gn/T/swift-generated-sources/@_swiftmacro_13SwiftDataTest11ContentViewV5items33_BCE1062261466603F5F86A688789BF68LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/qv/m7sk8kcd3713j3l4bg8wt1lw0000gn/T/swift-generated-sources/@_swiftmacro_13SwiftDataTest11ContentViewV5items33_BCE1062261466603F5F86A688789BF68LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/qv/m7sk8kcd3713j3l4bg8wt1lw0000gn/T/swift-generated-sources/@_swiftmacro_13SwiftDataTest11ContentViewV5items33_BCE1062261466603F5F86A688789BF68LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/qv/m7sk8kcd3713j3l4bg8wt1lw0000gn/T/swift-generated-sources/@_swiftmacro_13SwiftDataTest11ContentViewV5items33_BCE1062261466603F5F86A688789BF68LL5QueryfMa.swift" I tap the add button 3 times. I stop the app from Xcode. I start the app from Xcode. The data does not show in the list view. I repeat this to see if it corrects itself like the other app did, and it continues this behavior over 3 starts. If I start the app on the phone itself, tap the add button twice, kill the app from the app switcher, then restart the app, the data is shown in the list view. If I then run the app from Xcode, the data IS shown in the list view. I delete one item. Stop the app in Xcode. Start the app in Xcode. Both items are there. It did not register the delete from the last app launch.

Not yet. I wanted to see if this was a thing first. I’ll do that tomorrow.