Property "About" (Bio in Telegram) in TLUserFull always is null

[flyagaSL]

When I get full information about a user, the "About" field is always NULL. The code snippet below.

foreach (var memberUser in chatUsers)
                                {
                                    var rq = new TeleSharp.TL.Users.TLRequestGetFullUser { Id = new TLInputUser { UserId = memberUser.Id, AccessHash = (long)memberUser.AccessHash } };

                                    TLUserFull rUser = await client.SendRequestAsync<TLUserFull>(rq); 
                                }

Sorry about my English