ubuntu mate focal.4 adjusting display config causes part of screen to become unusable

[Chris Guiver]

Ubuntu-MATE 20.04.4 RC live test on
- dell [optiplex] 780 (c2q-q9400, 8gb, amd/ati cedar radeon hd 5000/6000/7350/8350)

My displays don't match default setup. To have it match my setup I need to

- swap left-right
- my left is landscape (no change needed here)
- my-right is portrait-left

** Expected

On perform the steps above; I expect both screens to be usable performing prior steps

** Actual

The lower section of the now portrait-left display is now a changing image, as I type this it's changing; though if I stop typing it's changing as the cursor on the firefox window blinks too (ie. very regular pattern).

What's in that lower section of the display appears to be made up from elsewhere on the screen.

See attached pictures

Please Note: I'm sure this is a duplicate report; but I didn't find it (for tagging of LIVE QA-test of focal.4 RC) thus this filing.. If/when I find it I'll mark it duplicate.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubuntu-mate-core 1.263
ProcVersionSignature: Ubuntu 5.13.0-30.33~20.04.1-generic 5.13.19
Uname: Linux 5.13.0-30-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu27.21
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.445.1
CurrentDesktop: MATE
Date: Tue Feb 22 08:42:08 2022
LiveMediaBuild: Ubuntu-MATE 20.04.4 LTS "Focal Fossa" - Release amd64 (20220221)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-mate-meta
UpgradeStatus: No upgrade log present (probably fresh install)

[Chris Guiver (guiverc)]

another pic; just shows different 'mess' on right-portrait display bottom

[Chris Guiver (guiverc)]

another pic - on right side screen you can now see the display configuration (purpose of this shot).

left dell 19" is landscape 1280x1024
right dell 19" is portrait (rotation left) 1280x1024

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1961750

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1961750

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]