Facebook login name field missing

I have a server, writtien in NodeJS and in it I'm requesting for some facebook user info given his access_token with the fbgraph module (version 1.1.0).

return Promise.promisify(graph.get)('me', { fields: 'picture,id,birthday,email,first_name,last_name,name,middle_name,link,timezone,updated_time,verified, ... access_token: token });

The access token is sent by the client side (android). The problem I'm facing is, that for a very small percentage of requests, the "name" field is missing in the response, although I get some other info like email, profile picture, ...

I thought that the "name" field was a part of the public_profile and is always provided, or can a user somehow set is as hidden?

via Anže Čuk