I have no idea why some fieds is null

[tszyuloveyou]

I have 5 models: User, AdmissionTestType, AdmissionTest, AdmissionTestHasCandidate, AdmissionTestOrders

User model:

<?php

namespace App\Models;

use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Support\Facades\DB;

class User extends Authenticatable
{
    protected $fillable = [
        'username',
        'password',
        'family_name',
        'middle_name',
        'given_name',
        'gender_id',
        'passport_type_id',
        'passport_number',
        'birthday',
    ];

    public function hasUnusedQuotaAdmissionTestOrder()
    {
        $orderTable = (new AdmissionTestOrder)->getTable();
        $return = $this->hasOne(AdmissionTestOrder::class)
            ->where('status', 'succeeded')
            ->whereHas(
                'attendedTests', null, '<',
                DB::raw("$orderTable.quota")
            );
        $quotaValidityMonths = config('app.admissionTestQuotaValidityMonths');
        if ($quotaValidityMonths) {
            $return->leftJoinRelation('attendedTests as attendedTests.type as type')
                ->where(
                    DB::raw("
                        if(
                            attendedTests.testing_at IS NOT NULL,
                            DATE_ADD(
                                attendedTests.testing_at,
                                INTERVAL type.interval_month + $quotaValidityMonths MONTH
                            ),
                            DATE_ADD(
                                $orderTable.created_at,
                                INTERVAL $quotaValidityMonths MONTH
                            )
                        )
                    "), '>=', now()
                );
        }

        return $return;
    }
}

AdmissionTestType model:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class AdmissionTestType extends Model
{
    protected $fillable = [
        'name',
        'interval_month',
    ];
}

AdmissionTest model:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class AdmissionTest extends Model
{
    protected $fillable = [
        'type_id',
        'testing_at',
        'maximum_candidates',
    ];

    public function type()
    {
        return $this->belongsTo(AdmissionTestType::class, 'type_id');
    }
}

AdmissionTestHasCandidate model:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Relations\Pivot;

class AdmissionTestHasCandidate extends Pivot
{
    use HasFactory;

    protected $fillable = [
        'test_id',
        'user_id',
        'order_id',
        'is_present',
        'is_pass',
    ];
}

AdmissionTestOrders model:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Facades\DB;

class AdmissionTestOrder extends Model
{
    protected $fillable = [
        'user_id',
        'quota',
        'status',
    ];

    public function tests()
    {
        return $this->belongsToMany(AdmissionTest::class, AdmissionTestHasCandidate::class, 'order_id', 'test_id');
    }

    public function attendedTests()
    {
        return $this->tests()->where('is_present', true);
    }
}

when I use: $user->hasUnusedQuotaAdmissionTestOrder, the id and user_id fields result is null
I need to add ->select(["$orderTable.*"]) on end of the left join to fix id and user_id fields result is null
I think this is not a good idea because if on other file when I want to load relation and load less field that cannot easy to do
other devloper need to open the model to know the relationship need to select {table}.id and {table}.user_id
I have no idea how let it better should be.