kubuntu 20.04.1 live qa-test, change of display alignment made display unusable

Kubuntu 20.04.1 daily QA-test on
dell [optiplex] 755 (c2d-e8300, 8gb, amd/ati radeon rv610/radeon hd2400 pro/xt)

When I adjusted display.settings to have landscape+portrait, the landscape display became unreadable, and I obviously made mistake as portrait was upside-down.. GUI isn't usable as menu is on unusable display

this box appears to have IDENTICAL files in /var/crash reported in https://bugs.launchpad.net/ubuntu/+source/kubuntu-meta/+bug/1889960 but are likely unrelated. They were `ubuntu-bug` reported

This will be filed against INCORRECT package sorry; I suspect it's radeon related..

Picture of screens
https://photos.google.com/share/AF1QipPcjlzMvHtKIQVmi4QLOaY1_yLPbhFXbYFA32iLRCIrT2NTwvY-EpOEh54vwF8g2A?key=M2gtdTN4YjZ2c3RLVWJPMXQ2YXliZ3JMMG1PSW9R

Much of the time the image shown on my-left display was changing (lower panel portion especially, also I think where cursor would be on terminal), about 3 changes per second, but at times it became static for awhile.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubuntu-desktop (not installed)
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.4
Architecture: amd64
CasperMD5CheckResult: pass
CasperVersion: 1.445.1
CurrentDesktop: KDE
Date: Sat Aug 1 05:46:46 2020
LiveMediaBuild: Kubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
SourcePackage: ubuntu-meta
UpgradeStatus: No upgrade log present (probably fresh install)