Laravel 5.0渴望加载打破关系

I have this repository (PaymentRepository) the partial of what I'm stack at is this:

$location_id = \Request::get('location');
$transactions = Payment::where($paymentCondition)->with(array(
    'client' => function($query) use ($location_id) {
        if($location_id) $query->where('location_id', $location_id);
    }))->paginate(50);

When there isn't a location picked the payment does have a relation available with client, this is what I see when dumping a record

#relations: array:1 [▼
    "client" => Client {#578 ▶}
]

After a location is picked, relation is immediately broken then dumping record shows this

#relations: array:1 [▼
    "client" => null
]

Though when I perform toSql to query and dump it, the result is this:

"select * from `payments`"

Does eager loading (with(array('client'=>) break a relationship?, currently Payment class has this connection with Client class:

public function client() {
    return $this->belongsTo('App\Client', 'client_id' ,'id');
}