Flutter Blue Plus Not Scanning Units on IOS

I’ve created an ble utility in flutter utilizing the flutter_blue_plus library, i used each scanning and promoting options.
In android promoting and scanning each are working with none concern.
In IOS Promoting is working however scanning just isn’t working.
Code for scanning

    widget.flutterBlue.scanResults.hear((Listing<ScanResult> outcomes) {
      for (ScanResult end in outcomes) {
        setState(() {
          _addDeviceTolist(
            outcome.system,
            outcome.rssi,
          );
        });
      }
    });
    widget.flutterBlue.startScan(
      withServices: [Guid('7ecbb852-c08c-11ed-afa1-0242ac120002')],
      allowDuplicates: true,
    );

How one can make scanning work in IOS Model of the appliance.