Thanks for the hint, Redstar7!
The Magpie was sitting in the tree behind the feeder, pretty early in the season - most likely searching seeds on the ground later.
I´ll add the Hooded Crows to our list - I have simply overseen them yesterday
When I remember right, the Chaffinch was also not seen upside on the feeder, but was added to the list when we noticed it hopping around on the ground.