User Profile

I have a Category model that's defined like so: @Model final class Category { @Attribute(.unique) var id: UUID var name: String var parent_id: UUID? //categories can be children of other categories init(id: UUID, name: String, parent_id: UUID?) { self.id = id self.name = name self.parent_id = parent_id } } And I'm getting my categories from an API call and putting it into my View: import SwiftUI import SwiftData struct CategoryView: View { @Environment(\.modelContext) private var modelContext @Query private var categories: [Category] @Query(filter: #Predicate<Category>{ $0.parent_id == nil }) private var top_level_categories: [Category] var spacing: CGFloat = 25 var body: some View { HStack() { Text("Categories") .font(.title.bold()) Spacer() Text("see all") } .padding([.bottom, .top], 0) VStack(spacing: 20) { ScrollView(.horizontal) { HStack(spacing: spacing) { ForEach(top_level_categories) { category in Text(category.name!) } } } } .onAppear{ getCategories() } } func getCategories() { get_refresh_token { token in guard let token = token else { return } var urlRequest = URLRequest (url: URL(string:"https://api.test.com/categories")!) urlRequest.httpMethod = "GET" urlRequest.addValue("application/json", forHTTPHeaderField: "Content-Type") urlRequest.addValue("Bearer \(token)", forHTTPHeaderField: "Authorization") URLSession.shared .dataTask(with: urlRequest) { (data, response, error) in do { if let data = data { let c = try JSONDecoder().decode([Category].self, from: data) c.forEach { modelContext.insert($0) } try? modelContext.save() } } catch { print(error) } }.resume() } } } This runs fine the first time I run the app but when I run it again, I get the following error: ForEach<Array<Category>, UUID, Text>: the ID XXXXXX-XXXX-XXXX-XXXX-XXXXXX occurs multiple times within the collection, this will give undefined results! Not sure why this is happening since I thought putting the @Attribute(.unique) on ID means that the same category won't get added twice?