SwiftUI: Data Persistance

Question

I am trying to keep the data entered by the user stored on the device (through a file), when the user closes the app and relaunches it. Currently it just always shows the sample data when the app was quit (swiped up).

.onAppear {
            collections = loadCollections()
            if collections.isEmpty {
                addSampleCollection()
            }
        }
        .onDisappear {
            saveCollections(collections: collections)
                }
        
    }
  func delete(at offsets: IndexSet) {
    collections.remove(atOffsets: offsets)
  }
    func saveCollections(collections:[Collection]){
        do {
            let encoder = PropertyListEncoder()
            encoder.outputFormat = .xml // or .binary for binary format

            let data = try encoder.encode(collections)
            let fileURL = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
                        .appendingPathComponent("Collections.plist")
            try data.write(to: fileURL)
           } catch {
            print("Error saving collections to property list: \(error)")
                   }
    }
    func loadCollections() -> [Collection] {
            do {
                let fileURL = try FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
                    .appendingPathComponent("Collections.plist")
                let data = try Data(contentsOf: fileURL)
                let decoder = PropertyListDecoder()
                return try decoder.decode([Collection].self, from: data)
            } catch {
                print("Error loading collections from property list: \(error)")
                return []
            }
        }
    func addSampleCollection() {
            let sampleCollection = Collection(title: "Sample Collection", description: "This is a sample collection", items: [
                Item(title: "Item 1"),
                Item(title: "Item 2"),
                Item(title: "Item 3")
            ])

            collections.append(sampleCollection)
        }
}

This is an extract from my ContentView.