Symfony2 cached controller won’t update

I’m quite new to PHP and have received some Symfony2 project to maintain. Now I’ve found out that when I update foo.html.twig, that page will not change until I perform the command console c:c -e prod. Until then the shown page will be foo.html_.twig (hence the underscore).

The problem is that I’ve changed a controller, let’s say BarController.php, but the new added value in that controller does not work in the .twig file, I think because the BarController_.php did not get updated with the clear cache command. What did I do wrong here?

Source: stackoverflow-php