sample.cs

public class UserAuth{
  ...
  public long UserID {get;set;}
}

User user = new User();
user.UserID = 100;
session.Store(user);
session.SaveChanges();

// json in data column with camelCase is {userID:100}

session.Query<User>().Where(x => UserID = 100);
// sql query = (d.data ->> 'UserID' = :arg1)

// no results, because json document contains { userID:100} and not { UserID: 100}