Realtime error 1008

 RealtimeSubscription subscribeToRealtimeUpdates(String collectionId) {
    try {
      print('started subscription to $collectionId');
      var subscription = Realtime(_client).subscribe([
        'databases.$kAppwriteDb.collections.$collectionId.documents',
      ]);
      print('listen to stream');
      subscription.stream.listen((event) {
        if (kDebugMode) {
          print('got event for appwrite: ${event.payload}');
        }
        add(
          RealtimeSubEvent(
            model: fromJsonT(event.payload),
          ),
        );
      }).onError((e) => _logger.severe('realtime error: $e')); // does also not help...
      return subscription;
    } catch (e, s) { // does nothing at all...
      _logger.severe(
        'realtime error DB: $kAppwriteDb; Collection $collectionId;',
        e,
        s,
      );
      rethrow;
    }
  }