Unable to start NEContentFilter on iOS

Previously, I added a post about the problem with NEFilterManager configuration. Since then, I explored the SimpleTunnel example project and I changed NEFilterManager setup to my own and it still worked well. Now, I simplified the code to just test that Content Filter is starting, but unfortunately it's displayed as 'Invalid' in System Settings.

Here are the samples of my code, but I still don't understand what I am doing wrong here. I would be very grateful for any help.

Test View

struct ContentFilterView: View {
    @ObservedObject var vm = FilterManager.shared
    @State private var toggleState = false 
    
    var body: some View {
        VStack {
            Toggle("Filter Status", isOn: $toggleState)
                .padding()
                .onChange(of: toggleState) { status in
                    vm.setupFilter(with: status)
                }
        }
        .onAppear {
            vm.loadFilterConfiguration { success in
                if success {
                    print("loadFilterConfiguration is successful")
                    toggleState = vm.isEnabled ?? false
                    print("NEFilterManager config: \(String(describing: NEFilterManager.shared().providerConfiguration?.organization))")
                } else {
                    print("loadFilterConfiguration failed")
                    toggleState = false
                }
            }
        }
    }
}

FilterManager

class FilterManager: ObservableObject {
    @Published
    private(set) var isEnabled: Bool? = nil
    
    // MARK: - Properties
    private let manager = NEFilterManager.shared()
    private var subs = Set<AnyCancellable>()
    static let shared = FilterManager()
    
    private init() {
        manager.isEnabledPublisher()
            .receive(on: DispatchQueue.main)
            .sink(receiveValue: { [weak self] isEnabled in
                self?.setIsEnabled(isEnabled)
            })
            .store(in: &subs)
    }
    
    public func setupFilter(with status: Bool) {
        if status && manager.providerConfiguration == nil {
            let newConfiguration = NEFilterProviderConfiguration()
            newConfiguration.username = "TestUser"
            newConfiguration.organization = "Test Inc."
            newConfiguration.filterBrowsers = true
            newConfiguration.filterSockets = true
            manager.providerConfiguration = newConfiguration
            
            print("manager configuration saved successfully: \(String(describing: manager.providerConfiguration?.organization))")
        }
        
        manager.isEnabled = status
        
        manager.saveToPreferences { [weak self] error in
            if let error {
                print("Failed to save the filter configuration: \(error.localizedDescription)")
                self?.isEnabled = false
                return
            }
        }
    }
    
    public func loadFilterConfiguration(withCompletion completion: @escaping (Bool) -> Void) {
        manager.loadFromPreferences { error in
            if let loadError = error {
                print("Failed to load the filter configuration: \(loadError)")
                completion(false)
            } else {
                completion(true)
            }
        }
    }
    
    private func setIsEnabled(_ isEnabled: Bool) {
        guard self.isEnabled != isEnabled else { return }
        self.isEnabled = isEnabled
        print("NEFilter \(isEnabled ? "enabled" : "disabled")")
    }
}


extension NEFilterManager {
    // MARK: - Publisher enabling
    func isEnabledPublisher() -> AnyPublisher<Bool, Never> {
        NotificationCenter.default
            .publisher(for: NSNotification.Name.NEFilterConfigurationDidChange)
            .compactMap { [weak self] notification in
                guard let self else { return nil }
                return self.isEnabled
            }
            .eraseToAnyPublisher()
    }
}

NEFilterDataProvider

class FilterDataProvider: NEFilterDataProvider {
    
    // MARK: - Properties
    /// A record of where in a particular flow the filter is looking.
    var flowOffSetMapping = [URL: Int]()
    /// The list of flows that should be blocked after fetching new rules.
    var blockNeedRules = [String]()
    /// The list of flows that should be allowed after fetching new rules.
    var allowNeedRules = [String]()
    
    override func handleNewFlow(_ flow: NEFilterFlow) -> NEFilterNewFlowVerdict {
        Log("Will handle filter flow \(flow)", prefix: "[Filter Data]")
        return .drop()
    }
}

NEFilterControlProvider is the same as SimpleTunnel example project NEFilterControlProvider implementation.

I also followed suggested steps mentioned in this post but it didn't seem to help.