Hi Moritz, I was following your Using Twig with ProcessWire article today to set up a site for using Twig and have come across a strange problem.
When I first started, I quickly created some templates and added a few words in them to see if they were rendering correctly.
Then I began working on the site properly. Everything was going fine until I tried to test a page in responsive view.
Suddenly, everything I'd been adding to my twig templates had disappeared and I was being shown the small amount of dummy text I'd started with, like a cached version of the very first page rendered.
I found that switching to responsive mode had logged me out of PW and it wasn't until I logged back in that everything I'd been working on displayed again.
The being logged out when switching to responsive mode is weird enough, but a separate issue, (setting $config->sessionFingerprint to false fixes it) but do you know what might be preventing my pages displaying correctly unless I'm logged in?