Unable to run BLE GATT service on Nordic Thingy 52

Oh, great. Thanks for the quick response. Switching Bluetooth on and off actually solved the problem!

I found a note in the meantime that the Bluetooth SIG requires a service 0x1801: { // generic attribute service with charactersitic 0x2A05: { // service changed characteristic to be present (and I assume with value true) if the services on a device can change.

I tried to set this, as part of my code using

NRF.setServices({
  0x1801: { // generic attribute service
    0x2A05: { // service changed characteristic
      notify: true,
      readable: true,
      value : [true]
    }
  }
});

but this didn't produce any effect. I suppose at that point it's already too late? Would it be possible to put that into the default profile?