I also logged https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics- drivers-340/+bug/1876551 about nvidia-340 drivers having the same problem (won't remember the config).
My workaround is a .desktop file that calls xrandr with my desired parameters I configured with nvidia tool and then dumped out with xrandr. ** Also affects: nvidia-graphics-drivers-340 (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1874567 Title: [nvidia] Rotating secondary monitor to portrait fails, results in landscape To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1874567/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs