Please restore the site from the backup, deactivate all the plugins not related to the theme and switch the parent theme, update the plugin once more, if the problem remains, provide the site admin access to the private area
Please make the full backup of your site as well as the Theme settings export and check the issue on the Storefront theme to detect if our theme causes the problem. If you see the same on the other theme, contact your host support. Our theme does not influence this.