I am getting an error in the onAddGeofencesResult(int statusCode, String[] geofenceRequestIds) callback with statusCode = 1000.
I have my GP
You actually gave the answer in your question: Geofence service is not available now. Typically this is because the user turned off location access in settings > location access.
I had this same issue, and just going to settings --> location and making sure I select the mode for high accuracy fixed this issue.
PS Device only mode is not good enough, it needs to be High accuracy mode.
Hope this helps.