Dear maintainers, GDM, GNOME, nvidia-driver and nouveau seems fine now, but ordinal ttys resolutions were decreased.
After all, I, root@buster# apt remove --purge nvidia-driver root@buster# reboot -n root@buster# nano /etc/apt/sources.list (remove contrib and non-free) root@buster# apt update root@buster# apt install xserver-xorg-video-nouveau # re-install root@buster# apt autoremove --purge root@buster# reboot -n and GDM, GNOME are fine. Mozilla Firefox plays youtube video both in window and fullscreen. no sound, though. I connect GeForce 1030 and LCD by HDMI cable. With that, Stretch was fine. Perhaps I should clean install by the next buster netinst, without contrib and non-free, again. I will report something went wrong after that. Sorry for junky reports. Thank you, all the maintainers. Regards.