Found the reason why. I had a locally cached database that was in conflict with the model (I changed the type of an attribute). I removed the cache as explained here and that fixed the issue

Found the path with that code : let urlApp = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask).last let url = urlApp!.appendingPathComponent("default.store") if FileManager.default.fileExists(atPath: url.path) { print("swiftdata db at \(url.absoluteString)") } THen once in that folder I did rm -rf default* And the local coach is gone!