Firebase Admin SDK Event Listener not triggered

I am using the Go Firebase Admin SDK and listening to changes in the Realtime Database. The problem is that the listener is ONLY triggered if I manually update the data from the Firebase Console, if I change data from another app (in this case Flutter), the listener is NOT triggered even though the changes can be seen in the Firebase Console (so the data definitely changed).

I even tried performing an update via Firebase Database REST API https://firebase.google.com/docs/reference/rest/database#section-streaming
Which had the same result: Data changes are viewable in the Console, but still don't trigger the listener.

Here the way I'm listening to changes in Go:

func listenToFirebase(ref *db.Ref, ctx context.Context) {
    iter, err := ref.Listen(ctx)
    if err != nil {
        fmt.Printf(" Error: failed to create Listener %v\n", err)
        return
    }
    defer iter.Stop()

    for {
        if iter.Done() {
            break
        }
        event, err := iter.Next()
        if err != nil {
            // Handle error here based on specific usecase
            // We can continue Listening
            log.Printf("%v\n", err)
            continue
        }
        fmt.Printf("Listener | Ref Path: %s | event.Path %s | event.Snapshot() = %v\n", ref.Path, event.Path, event.Snapshot())
        fmt.Printf("\n")
    }
}

The fact that the listener is triggered by updating data from the Console, indicates that the listener is working properly.

P.S.: The Listen-Method has not yet been integrated to the Go Firebase Admin SDK and is from https://github.com/firebase/firebase-admin-go/issues/229