laravel env method get different value when code not change ？

I'm new beginner of laravel.I want use Helpers to get environment value using env method.

class Helpers {
  public static function somefunc(){
    var_dump(env('QINIU_BUCKET_DOMAIN'));exit;
  }
}

Then strange thing happed.When I opened chrome-dev-tool (F12),I got nothing. Then I closed chrome-dev-tool,I got what I want. Is anything wrong? Anybody can help me? :)

via Chebli Mohamed