Uncaught InternalError: BLE task completed that wasn't scheduled (3/4)

The same error is returned when trying to get the primary service of my laptop from bangle js. I implemented a Gattserver solution on my laptop advertsing a costant value (as explained in UWP sample on Microsoft website): the bangle successuflly connects to my laptop but on finding primary services the code run into the same error. I suppose it's not able to find the service even if on scanning BLE devices nearby with relative services it seems to be visible. Here my JS code:

function ReceiveData(d) { 
  g.drawString(d, g.getWidth()/2, g.getHeight()/2); 
}


Bluetooth.on('data', function(d) { 
  g.clear();
  g.setFont("Vector", 10);
  g.setColor(0,255,0);
  setTimeout( () => (g.drawString(Serial.read(), g.getWidth()/2, g.getHeight()/2)), 5000);
  setTimeout( () => (g.drawString('Data received', g.getWidth()/2, g.getHeight()/2)), 2000);
  });

NRF.on('connect', function(addr) {
  g.clear();
  g.setFont("Vector",10);
  g.setColor(255,0,0);
  g.drawString(addr,g.getWidth()/2, g.getHeight()/2);
  g.setFont("Vector",25);
  setTimeout(()=>g.drawString("Connected", g.getWidth()/2, g.getHeight()/2), 3000);
  setTimeout(()=>g.clear(),1000); 
  Connect(macaddress);
});

NRF.on('disconnect', function(reason) {
  g.clear();
  g.setColor(0,0,255);
  g.drawString("Disconnected", g.getWidth()/2, g.getHeight()/2);
  setTimeout(()=> g.clear(), 1000);
});

function Scandevices(){
  var devices;
  NRF.findDevices(function(d) {
  devices = d;
  console.log(devices);
  }, {timeout : 2000, filters : [{ manufacturer: "6"}] });
  }

function Connect(){
  NRF.connect(macaddress).then(function(g) {
    gatt = g;
    return gatt.startBonding(); 
    }).then(function(service) {
    try{
        console.log(gatt.getSecurityStatus());
        console.log("Connected");
        return gatt.getPrimaryService(serviceUid).catch(onRejected);
    }
    catch(exception){
      console.log(exception);
    }
      console.log("Service");
      return service.getCharacteristic(characteristcUid).catch(onRejected);}).then(function(characteristic) {
        //console.log(characteristic);
        //console.log("Got:", JSON.stringify(d.buffer));
        });
}

function onRejected(event){
  console.log('The code run into a problem: '+ event);
}




// Code

g.setFontAlign(0,0); 
g.setFont("Vector",25);
delay = 5000;

var gatt;
macaddress = "58:74:96:7c:53:b0" + " private-resolvable";
serviceUid = 'f150e6c7-0db4-4645-ae74-023c39598372';
characteristicUid = "b952f9c0-218d-42b6-8ee6-4aab35753922";

Scandevices();
setTimeout(Connect, delay);

After printing "Connected" the error appears!