Route resulted in a `404 Not Found` response but works perfectly sometimes

I do not come with a background in web apps, I'm trying to fix this issue on a project where a route is called in a function call and sometimes it says "404 not found" all tho it exists in route:list.

This is the function call as follows:

function call_api($method,$req){
    $client = new \GuzzleHttp\Client();
    $url = env('APP_URL')."api/".$method;
   
    $myBody = $req;
   
    $response = $client->post($url,['form_params'=>$myBody]);
    $result_array = json_decode((string) $response->getBody());

    $cont = $result_array;
    return $cont;
}

route controller:

public function web_category_list(Request $request){
        try{
        $news_details= Category::orderBy('id','desc')->post();
        $result['error_code'] = '200';
        $result['data'] = $news_details;
        return response()->json($result);
        }
       catch (Exception $e) {
       return response(['message' => $e->getMessage(), 'error_code' =>'404']);
      }