The changes in /etc/nvidia/current/nvidia-drm-outputclass.conf solve the Problem and works. But after Kernelupdate to linux-image-4.16.0-2-amd64 (4.16.16-1) boot into a black Screen, 4.16.12-1 workd fine. Same Problem like this Bug https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=901932 Holger...