早速どうもありがとうございます。

site-2023-10-23.log を見てみました。Error 表示が多いのですが

[2023-10-23 14:48:57] php.INFO [4495d8ec1e699537208b1e9e8c9b267b] [5f21e69] [1] [Symfony\Component\Debug\ErrorHandler:handleError:528] - User Deprecated: The "Eccube\Repository\BaseInfoRepository" service is private, getting it from the container is deprecated since Symfony 3.2 and will fail in 4.0. You should either make the service public, or stop using the container directly and use dependency injection instead. {"exception":"[object] (ErrorException(code: 0): User Deprecated: The \"Eccube\\Repository\\BaseInfoRepository\" service is private, getting it from the container is deprecated since Symfony 3.2 and will fail in 4.0. You should either make the service public, or stop using the container directly and use dependency injection instead. at /home/（アカウント名）/（アカウント名）.netshop.jp/public_html/vendor/symfony/dependency-injection/Container.php:282)"} [GET, /owner/store/plugin/api/search, 222.146.89.77, https://（アカウント名）.netshop.jp/owner/content/page/3/edit, Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/118.0]
[2023-10-23 14:48:57] php.INFO [4495d8ec1e699537208b1e9e8c9b267b] [5f21e69] [1] [Symfony\Component\Debug\ErrorHandler:handleError:528] - User Deprecated: The "Eccube\Service\Composer\ComposerApiService" service is private, getting it from the container is deprecated since Symfony 3.2 and will fail in 4.0. You should either make the service public, or stop using the container directly and use dependency injection instead. {"exception":"[object] (ErrorException(code: 0): User Deprecated: The \"Eccube\\Service\\Composer\\ComposerApiService\" service is private, getting it from the container is deprecated since Symfony 3.2 and will fail in 4.0. You should either make the service public, or stop using the container directly and use dependency injection instead. at /home/（アカウント名）/（アカウント名）.netshop.jp/public_html/vendor/symfony/dependency-injection/Container.php:282)"} [GET, /owner/store/plugin/api/search, 222.146.89.77, https://（アカウント名）.netshop.jp/owner/content/page/3/edit, Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/118.0]

この２つと、
[2023-10-23 15:39:33] php.INFO [4495d8ec1e699537208b1e9e8c9b267b] [d24729e] [1] [Symfony\Component\Debug\ErrorHandler:handleError:528] - User Deprecated: The "Sensio\Bundle\FrameworkExtraBundle\Configuration\Route" annotation is deprecated since version 5.2. Use "Symfony\Component\Routing\Annotation\Route" instead. {"exception":"[object] (ErrorException(code: 0): User Deprecated: The \"Sensio\\Bundle\\FrameworkExtraBundle\\Configuration\\Route\" annotation is deprecated since version 5.2. Use \"Symfony\\Component\\Routing\\Annotation\\Route\" instead. at /home/（アカウント名）/（アカウント名）.netshop.jp/public_html/vendor/sensio/framework-extra-bundle/Configuration/Route.php:16)"} [GET, /owner/setting/nextshop/account_setting, 222.146.89.77, https://（アカウント名）.netshop.jp/owner/setting/system/log, Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/118.0]

だいたいこの繰り返しのようなのです……。
よくわかっていなくてすみません、どうぞよろしくお願いします。