title: BLUETOOTH - Linux: Changing advertisement of appearance with bluetoothctl fails
body: <p>I like to use a RaspberryPi to act as HeartRate Sensor and transmit these data via BLTH to other Health/Sport-Apps.
  Finally all is working fine with python and bluez I'm able to create a BLTH GATT Server and advertise  HR-Data via Service 0x180d.</p>
  <p>The last problem is I'm not able to change the Appearance of the BLTH in Generic Access (0x1800). Apprearance is to find here with UUID: 0x2A01.</p>
  <p>I tryed to do this the manual way via bluetoothctl:
  menu advertise
  appearance 833 (for HeartRate)
  appearance on
  back
  advertise on</p>
  <p>This will fail with: Failed to register advertisement: org.bluez.Error.Failed</p>
  <p>nevermind to which value i change the apperance (also if the value is well known and accepted) it fail the advertisement.
  If i switch appearance off it will start advertisment.
  Any hint, what do to or what I just missed?
  I already updated bluez from 5.50 to 5.54
  also used bluez in experimental mode</p>
  <ul>
  <li>and using newest raspian os with all updates</li>
  </ul>
  <p>Many thanks for help</p>