I tried this on android, no Bluetooth devices found I am using flutter_blue

 FlutterBlue flutterInstance = FlutterBlue.instance;

  void _scanBT() {
    // this line will start scanning bluetooth devices
    flutterInstance.startScan(timeout: Duration(seconds: 4));
    var scanDevices = flutterInstance.scanResults.listen((scanResult) {
    }); // this line will stop scanning bluetooth devices

Solution 1: Felipe Vergara

This problem is very common when your devices have turn off her GPS.

If you active the GPS in both devices then you will find your devices.

PD: Make sure that your devices are visibles to other devices (In bluetooth settings)