I don't use Arch, so I can's say for sure. And I don't speak German(?) so I can't tell what it is that you're sharing with us in the screenshots. However, I can say that only set my printers up in the cups webpage. Otherwise I run into issues all the time (sharing seems to never work from the gui). Try setting it up with http://localhost:631/. Make sure you're using the exact same driver you used when it worked in Ubuntu.