NRF.setScan() stops working

Hi. I am having a problem when calling a function inside NRF.setScan():

NRF.setScan(function(d) {
    if (d.id === "xxxx") { 
          //do some stuff here
          setState([0xCC, 0x24, 0x33]); }
}

When I call setState(), it doesn't return to NRF.setScan:

function setState(arg) {
    var gatt;  
    NRF.connect(addr).then(function(g) {
      gatt = g;
      return gatt.getPrimaryService("0000ffe5-0000-1000-8000-00805f9b34fb");
    }).then(function(service) {
      return service.getCharacteristic("0000ffe9-0000-1000-8000-00805f9b34fb");
    }).then(function(c) {
      characteristic = c;
      return characteristic.writeValue(arg);
    }).then(function() {
      gatt.disconnect();
    });
  }

Any idea why? Other functions return properly, something to do with NRF.connect maybe?