The Multisite Language Switcher does not redirect the users automatically. I'm not sure if the plugin should do that. You might check out this <a href="https://github.com/danieledesantis/jquery-language-detection">jQuery plugin</a> or <a href="https://github.com/oncleben31/Multisite-Language-Switcher-Theme">this approach with a theme</a> if you need such functionality.