The system which automatically configure the position and size of the display seems to not handle the display viewport correctly.
When configuring the position of displays with Ubuntu display settings interface, If I set a vertical display (rotated 90°) for a 1920x1080 display, then it seems the viewport or virtual display (I don't really know how you name is) seems to be 1920x1920. So the desktop is bigger than the screen and it can be moved with the mouse. Considering I use multi screens (3 rotated and one normal) it makes some crazy things.
So my feeling is that while the screen is rotated, the viewport definition remains 1920x1080 instead of 1080x1920, and the system resolve it by providing a viewport of 1920x1920.
This issue can be more or less circumvented using Nvidia Tools to configure displays. With it, the viewport seems to work correctly. However, as soon as a screen is disconnected, the system reconfigure the various displays and the issue comes back. So often, after a sleep or something like that, the issue comes back.
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ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
DisplayManager: gdm3
DistroRelease: Ubuntu 20.04
InstallationDate: Installed on 2019-04-30 (383 days ago)
InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
NonfreeKernelModules: nvidia_modeset nvidia
Package: gnome-shell 3.36.1-5ubuntu2
PackageArchitecture: amd64
ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30
RelatedPackageVersions: mutter-common 3.36.1-3ubuntu3
Tags: focal
Uname: Linux 5.4.0-29-generic x86_64
UpgradeStatus: Upgraded to focal on 2020-05-08 (10 days ago)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
_MarkForUpload: True
Additionnal information about my system:
Ubuntu 20.04 64bits
Amd ryzen 2700
Dual Nvidia Geforce 980ti with all displays plugged on the same card
Nividia drivers 440 provided by Ubuntu
4 Displays:
- 3 x 1920*1080 rotated 90°
- 1 x 4k normal orientation