Live Activity updates succeed (plugin logs) but widget always shows Swift defaults (iOS 18.2, Flutter)

[yarenalbayr]

I’m seeing a puzzling behavior: the Live Activity starts and renders on the Lock Screen/Dynamic Island, and Flutter logs report that updateActivity(...) calls succeed with the full payload. However, the widget UI never reflects those updates—it only shows the default values defined in Swift.

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Environment

• Flutter: stable (iOS, physical device)

• Plugin: live_activities: ^2.4.2

• Device iOS: 26.0.1

• Runner (app) min iOS: 13

• Extension min iOS: 18.2 (Live Activities supported; also annotated with @available(iOSApplicationExtension 16.1, *))

• Xcode: 26.0.1

• Entitlements:

  • App and Extension: Live Activities + App Groups
  • App Group: group.com.example.app (redacted)

• Embedding: Extension embedded via Build Phases → Embed Foundation Extensions → Destination: Plugins and Foundation Extensions

• Runner Target Dependencies includes the extension; Skip Install = Yes on extension

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Symptom

• createActivity(...) returns an ID and Live Activity renders.
• Repeated updateActivity(...) calls log “updated successfully” with full state.
• UI remains on Swift defaults (never reflects Flutter-sent values).

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Minimal Repro (Dart)

await live.init(appGroupId: 'group.com.example.app', urlScheme: 'vns');

final id = await live.createActivity(
  'LiveActivitiesAppAttributes', // also tried '<EXTENSION_TARGET_NAME>.LiveActivitiesAppAttributes'
  {
    'name': 'Stress Session',
    'state': 'active',
    'endTime': '16:33',
    'statusMessage': 'Session started',
    'intensity': 1,
    'isPaused': false,
  },
);

await live.updateActivity(id, {
  'name': 'Stress Session',
  'state': 'active',
  'endTime': '16:33',
  'statusMessage': 'Intensity level 2',
  'intensity': 2,
  'isPaused': false,
});

---

Widget (Swift, simplified)

I tried both paths: reading directly from context.state.* and reading from App Group UserDefaults using a prefixed key. Neither path reflects Flutter updates; the UI stays on defaults.

import ActivityKit
import WidgetKit
import SwiftUI
import AppIntents

private func appGroupId() -> String { "group.com.example.app" }
let sharedDefaults = UserDefaults(suiteName: appGroupId())!

struct LiveActivitiesAppAttributes: ActivityAttributes, Identifiable {
  public typealias LiveDeliveryData = ContentState
  public struct ContentState: Codable, Hashable {
    var name: String?
    var emoji: String?
    var state: String?
    var endTime: String?
    var statusMessage: String?
    var intensity: Int?
    var isPaused: Bool?
  }
  var id = UUID()
}

@available(iOSApplicationExtension 16.1, *)
struct SessionLiveActivity: Widget {
  var body: some WidgetConfiguration {
    ActivityConfiguration(for: LiveActivitiesAppAttributes.self) { context in
      // Path A: direct ContentState (tried this)
      // let sessionName = context.state.name ?? "Default"

      // Path B: App Group defaults (tried this as a sanity test)
      let sessionName = sharedDefaults.string(forKey: context.attributes.prefixedKey("name")) ?? 

<img width="603" height="208" alt="Image" src="https://github.com/user-attachments/assets/b4c7b1cc-f1ba-42ee-a431-a30b1e82496e" />

      let endTime = sharedDefaults.string(forKey: context.attributes.prefixedKey("endTime")) ?? "00:00"
      let statusMsg = sharedDefaults.string(forKey: context.attributes.prefixedKey("statusMessage")) ?? "active"
      let intensity = sharedDefaults.integer(forKey: context.attributes.prefixedKey("intensity"))
      let isPaused = sharedDefaults.bool(forKey: context.attributes.prefixedKey("isPaused"))

      VStack {
        Text(sessionName)
        Text(endTime)
        Text(statusMsg)
        Text("\(intensity)")
        Text(isPaused ? "paused" : "active")
      }
    }
  }
}

extension LiveActivitiesAppAttributes {
  func prefixedKey(_ key: String) -> String { "\(id)_\(key)" }
}

---

Logs (trimmed)

[log] Live Activities service initialized successfully
[log] Creating new Live Activity: {name: Stress Session, emoji: ⚡, state: active, endTime: 16:33, statusMessage: Session started, intensity: 1, isPaused: false}
[log] Live Activity created successfully with ID: 148D781F-E307-446B-AEC4-DA2D80A9B012
[log] Sending Live Activity update with full state: {name: Stress Session, emoji: ⚡, state: active, endTime: 16:33, statusMessage: Intensity level 1, intensity: 1, isPaused: false}
[log] Live Activity updated successfully
[log] Sending Live Activity update with full state: {... intensity: 2, ...}
[log] Live Activity updated successfully

---

What I’ve already tried

• ✅ Runner → Target Dependencies includes extension
• ✅ Extension Skip Install = Yes
• ✅ Entitlements on both targets: Live Activities, App Groups (group.com.example.app)
• ✅ Build once in Xcode; physical device
• ✅ Tried passing module-qualified type: '<EXTENSION_TARGET_NAME>.LiveActivitiesAppAttributes'
• ✅ Renamed state → sessionState in both keys and Swift struct (to dodge any reserved-name quirks)
• ✅ iOS 17-only Button(intent:) controls are availability-gated (not relevant to this decode issue)
• ✅ Also tested reading state via UserDefaults (App Group) with prefixed key—UI still shows defaults

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Redaction

• Bundle IDs, group IDs, and product names are replaced with placeholders like group.com.example.app and <EXTENSION_TARGET_NAME>.

---

Any pointers appreciated

If there’s a known requirement to compile the attributes in both targets (app + extension) when using Flutter, or another gotcha that produces this “defaults only” behavior despite successful updates, I’d love guidance.

[istornz]

Hello @yarenalbayr, thanks for raising an issue.
Can you try to launch the example football on the same device and check if creation / update of the live activity is working properly or not?

Thanks