Badly working video mode on the greeter

[Jarno Suni]

In the video mode there are moving stripes on the screen and monitor turns off occasionally. (Maybe this is just bad behaving monitor, an old Samsung TV) It became got good after I run

xrandr --output HDMI-1 --mode 1920x1080

(and --auto for each other video output) in /usr/local/bin/monitor-config.sh and I put

display-setup-script=/usr/local/bin/monitor-config.sh

in LightDM configuration, except that screens partly overlap even if the other monitor is right of other. Couldn't they be mirroring each other? Anyway, I can make it work decently as extended desktop if I use --left-of or --right-of.

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: lightdm 1.30.0-0ubuntu1
ProcVersionSignature: Ubuntu 5.3.0-29.31-generic 5.3.13
Uname: Linux 5.3.0-29-generic x86_64
ApportVersion: 2.20.11-0ubuntu8.2
Architecture: amd64
CurrentDesktop: XFCE
Date: Thu Feb 6 13:35:12 2020
InstallationDate: Installed on 2019-12-05 (62 days ago)
InstallationMedia: Xubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
LightdmConfig:
 [Seat:*]
 display-setup-script=/usr/local/bin/monitor-config.sh
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)