Resolved: advertising a GATT service (heart rate) does not work but UART does

Hey there I got your example working using following code:

  NRF.setServices({
  0x180D: { // heart_rate
    0x2A37: { // heart_rate_measurement
      notify: true,
      value : [0x06, 0],
    }
    }
  }, { advertise: [ '180D' ] });
  
  Bangle.setHRMPower(1);
  Bangle.on('HRM', function(hrm) {
    NRF.updateServices({
      '180d': {
        '2a37': {
          value: [0x06, hrm.bpm],
          notify: true
        }
      }
    });
  });

With this code, I could see the heart rate inside the nRF connect app as well as in FitoTrack for Android. However, I got two problems to solve: First, setServices requires a BLE restart. Secondly, if the device is already connected to e.g. gadgetbridge it is not discoverable except when I trigger it within the bluetooth settings.