URL error on page displaying search results

I want to add a store information search field to the top page of a site created with laravel and display the search results on a separate page.
Currently, pressing the "Search" button results in a 404 error.
The URL at that time is "example.com/shop/search?keyword=&"category"=".
Nothing in error.log. where is the cause?

Code
php artisan route:list

| GET|HEAD  | shop/search   | shop.search                  | App\Http\Controllers\ShopController@search                                  | web 

home.blade.php

    <div class="c-form__select">
        <form method="GET" action="{{ route('shop.search')}}">
        <input name="keyword" type="text" placeholder="Enter Keyword" value="{{ $params['keyword'] ?? null }}">
        <select name="category" class="c-form__control">
            <option selected="selected" value="">Please select</option>
            @foreach($categories as $category)
            <option value={{ $category->id }}> {{ $category->name }}</option>
            @endforeach
        </select>
        <button type="submit">Search</button>
    </form>
    </div>

Search.blade.php

    <div class="l-section_bgpink l-section"><div class="l-section__inner">
        @if (!$shops->isEmpty())
        <ul class="c-shop">
            @foreach ($shops as $shop)
            <li><a href="{{ route('shop.show', ['shop' => $shop]) }}">
                <div class="logo"><img src="{{ $shop->logo ? asset('storage/'.config('constants.UPLOAD_IMG_SHOP').'/'.$shop->logo) : asset('/assets/img/shop/img_noimage.jpg') }}" alt="{{ $shop->name }}"></div>
                <div class="name">{{ $shop->name }}</div>
            </a></li>
            @endforeach
        </ul>
        @else
        <p class="c-txt">Your store is not registered.</p>
        @endif
</div></div>

ShopController.php

    public function search(Request $request)
    {
        $params = $request->query();

        $shops= Shop::scopeSearch($params)->get();

        $slides = Slide::where([
            ['area_id', '=', config('constants.AREA_ID')],
            ['status', '=', 1],
        ])->orderBy('created_at')->get();

        return view('shop.search', [
            'shops' => $shops,
            'slides' => $slides,
        ]);
    }

App/Models/Shop.php

/**
 * @param \Illuminate\Database\Eloquent\Builder
 * @param array
 * @return \Illuminate\Database\Eloquent\Builder
 */
public function scopeSearch(Builder $query, array $params): Builder
{

    if (!empty($params['category_id'])){
        $query
        ->where(['area_id', '=', config('constants.AREA_ID')],
                ['category_id', '=', $id],
                ['status', '=', '1']);
    }

    // keywords
    if (!empty($params['keyword'])) {
        $query->where(function ($query) use ($params) {
            $query->where('name', 'like', '%' . $params['keyword'] . '%')
                ->orWhere('region', 'like', '%' . $params['keyword'] . '%')
                ->orWhere('back', 'like', '%' . $params['keyword'] . '%')
                ->orWhere('salary_assessment', 'like', '%' . $params['keyword'] . '%')
                ->orWhere('memo', 'like', '%' . $params['keyword'] . '%')
                ->orWhere('greeting', 'like', '%' . $params['keyword'] . '%');
        });
    }

    return $query;
}

web.php

    Route::get('shop/search', 'ShopController@search')->name('shop.search');