[Bug]: BackgroundGeolocation repeatedly posts stale location instead of current coordinates When

[KyungRyul]

Required Reading

• Confirmed

Plugin Version

5.1.2

Flutter Doctor

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.35.2, on macOS 15.6 24G84 darwin-arm64, locale ko-KR)
[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 26.1.1)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2025.1)
[✓] Connected device (3 available)
[✓] Network resources

Mobile operating-system(s)

• iOS
• Android

Device Manufacturer(s) and Model(s)

Galaxy S20, iPhone 12

Device operating-systems(s)

iOS 26.1, Anroid 13

What happened?

When the user is moving, location updates are successfully posted to the server. However, after some time, when a new location should be sent, the plugin repeatedly posts an old coordinate from a previously visited location instead of the user's current position.

For example:

The user moves from Point A to Point B to Point C.
Initially, the server receives the correct coordinates.
Later, instead of sending the current location, it continuously sends the coordinates of a past location (such as Point B), even though the user has already moved elsewhere.

Plugin Code and/or Config

bg.BackgroundGeolocation.ready(bg.Config(
      geolocation: bg.GeoConfig(
        desiredAccuracy: bg.DesiredAccuracy.high,
        distanceFilter: 30,
        deferTime: 3000,
        pausesLocationUpdatesAutomatically: false,
        geofenceModeHighAccuracy: true,
        useSignificantChangesOnly: Platform.isIOS,
        fastestLocationUpdateInterval: 60000,
        locationUpdateInterval: 300000,
        locationAuthorizationRequest: 'Always',
        locationAuthorizationAlert: {},
      ),
      app: bg.AppConfig(
        preventSuspend: true,
        heartbeatInterval: 600,
        stopOnTerminate: false,
        startOnBoot: true,
        enableHeadless: true,
        notification: bg.Notification(),
        backgroundPermissionRationale: bg.PermissionRationale(),
      ),
      http: bg.HttpConfig(
        url: "${Constants.url}/api/user_position",
        params: {"uid": _auth.currentUser!.uid},
        headers: {"Content-Type": "application/json"},
        rootProperty: 'data',
      ),
      activity: bg.ActivityConfig(),
    )).then((bg.State state) {
      if (!state.enabled) {
        bg.BackgroundGeolocation.start();
      }
    });

Relevant log output

[christocracy]

See API docs LoggerConfig. Provide verbose logs.

[brneas]

I'm seeing this in v5.1.2 but unfortunately don't have any logs to provide yet.
I'll see what I can do about getting some logs for you but I honestly don't know how to reproduce the issue. It's one of those that seems random to me.

I can see in my production database that duplicate coordinates are coming through from the same time but they are being inserted into my database at differently times. With the precision of the latitude/longitude it should be pretty hard to get the exact same coordinates.
Here is a snippet of the database:

I've excluded some information but there should be enough info here to see the issue. My CreatedAt column is the datetime from flutter_background_geolocation and my InsertedAt time is the datetime that value was entered into my database. You can see multiple duplicate position rows that were all created on the device at the same time but hit my API at different times.
It is weird that odometer, activity ,and battery seem to change but everything else is the exact same.

I upgrade from v4.18.0 about 3 weeks ago and have noticed this issue over the past couple weeks since that upgrade.

I am using HttpConfig within flutter_background_geolocation to post these events:
http: bg.HttpConfig( autoSync: true, autoSyncThreshold: 10, url: "https://example.net/LogLocation", headers: { 'authToken': authToken, 'deviceId': deviceId, }, batchSync: true, maxBatchSize: 30, ),

Let me know if I can provide any other information and I'll see what I can do about getting some logs.