The output of the command setxkbmap -print on the linux host is:
xkb_keymap {
xkb_keycodes { include “evdev+aliases(qwertz)” };
xkb_types { include “complete” };
xkb_compat { include “complete” };
xkb_symbols { include “pc+de(nodeadkeys)+inet(evdev)” };
xkb_geometry { include “pc(pc105)” };
};
Meanwhile, I’ve connected from a Windows Client to the Linux host and got the same result, incorrect German keyboard mapping. So I guess it must be a problem on the host.