Laravel's dd on ajax called methods returns always empty attributes

I'm having pain with an ajax called method.

First the same request as above :

$usersData = User::where('name', 'like', $queryString . '%')
            ->orWhere('email', 'like', $queryString . '%')
            ->orWhere('username', 'like', $queryString . '%')
            ->when($limit > 0 || $offset > 0, function ($usersData) use ($limit, $offset) {
                $usersData->take($limit)->skip($offset);
            })
            ->with(array('roles'=>function($query){
                $query->select('name');
            }))
            ->get();

works perfectly in the index method, the dd is correct and 'roles' contain just the 'name' field BUT if i call exactly the same request 'roles' contain ALL attributes and dd does'nt work i'm forced to make a console.log of my datas I'm going mad !!!

Thanks for your help.

via Chebli Mohamed