On my eZ publish 5 site I have all my templates in Twig, in the vendor/ezsystems/demobundle/EzSystems/DemoBundle/Resources/views/ subfolders. They are all being used throughout my whole site, no problems there. With one exception: 404 pages. If I go to mysite/nonexistingurl, it gives me a kernel (20) / Error page, with status 404. The template being used for this is the 20.tpl somewhere in eZ publish/symfony, I don't want that, I want to use my own Twig template for this.
How can I achieve this? I added a vendor/ezsystems/demobundle/EzSystems/DemoBundle/Resources/views/Exception/error.html.twig page, but this one is not being called