changing monitor configuration & on next login, only one monitor is fully usable to LXQt

Bug #2013074 reported by Chris Guiver
This bug affects 1 person
Affects Status Importance Assigned to Milestone
openbox (Ubuntu)

Bug Description

Lubuntu lunar daily QA-test (live) on
- hp prodesk 400 g1 sff (i5-4570, 8gb, amd/ati cedar radeon hd 5000/6000/7350/8350)

this issue is NOT unique to Lubuntu; I've been experiencing it a lot on Debian lately; which is why I looked for it here (tonight) on this LIVE QA-test..

I also experience it on occasion on my primary box; just logout & login again usually resolves it there (in Debian too).

To avoid the issue; replace OPENBOX with XFWM4 or another & it won't occur, thus the filing against openbox.

** To re-create

- adjust monitors (how they are positioned to each other)
- logout
- login

** additional notes

- the logout/login may require a numerous attempts times to occur
- if it doesn't occur in 3-4 logout/login loops; adjust monitor alignment again & try again.
- it's occurred with monitors left+right aligned, top-bottom aligned & other combinations too YET i have had alignments where I DO NOT EXPERIENCE the issue too..
- occurs on boxes where I have 2, or 3 monitors attached
- this has occurred on installed systems (Debian bookworm & lunar), filed when I experienced it on LIVE lunar QA-test
- this bug is EASIER TO REPLICATE when one screen is vertically above another.. most users have side-by-side arrangements so likely won't be impacting many users

** Expected result

- on login, all are both usable, have wallpaper (half/third of wallpaper on each)
- right click on background pulls up menu

** Actual result

here it's inconsistent... Much of the time the result is Expected result


logout/login a few times & depending on how monitors are positioned you may get

- one monitor (or more) has the expected wallpaper but one is drawn without wallpaper & you're experiencing this issue.
- the monitor with wallpaper will operate normally & can hold windows
- one (or more) monitor will have no wallpaper & thus right-click on background will do nothing
- you cannot drag/drop windows from monitor with wallpaper to monitor that is black
- mouse (pointer) moves over black monitor as expected (ie. monitor exists & will take mouse-pointer normally, but windows won't draw on it if dragged to that window... if windows are dropped here they'll be inaccessible.. but if held & dragged across the black monitor & the drag continues to the wallpaper drawn monitor you can drop & use windows normally
- if panel is on black monitor (with only mouse-pointer being drawn on it) then panel+menu cannot be seen on that monitor/used, but it appears to be working; is just unseen (as are probably windows dropped there).

ProblemType: Bug
DistroRelease: Ubuntu 23.04
Package: openbox 3.6.1-10ubuntu1
ProcVersionSignature: Ubuntu 6.2.0-18.18-generic 6.2.6
Uname: Linux 6.2.0-18-generic x86_64
ApportVersion: 2.26.0-0ubuntu2
Architecture: amd64
CasperMD5CheckResult: unknown
CasperVersion: 1.480
CurrentDesktop: LXQt
Date: Tue Mar 28 12:22:27 2023
LiveMediaBuild: Lubuntu 23.04 "Lunar Lobster" - Alpha amd64 (20230325)
SourcePackage: openbox
UpgradeStatus: No upgrade log present (probably fresh install)

Revision history for this message
Chris Guiver (guiverc) wrote :
Chris Guiver (guiverc)
description: updated
Revision history for this message
Ubuntu QA Website (ubuntuqa) wrote :

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

A list of all reports related to this bug can be found here:

tags: added: iso-testing
Revision history for this message
Chris Guiver (guiverc) wrote :

Likely related -

On a live (lunar) test today on

- hp 8200 elite sff (i5-2400, 8gb, nvidia quadro 600)

I was able to get one screen impacted by 1845756 (screen was grey instead of wallpaper, but OBMENU appeared on right-click) & other screen black impacted by this bug..

As the OBMENU appeared; I could select RESTART OPENBOX which cleared the grey (replaced by wallpaper on one display) & then had LXQt menu appear on that display... no PANEL still as that was on the screen impacted by this bug...

Revision history for this message
Chris Guiver (guiverc) wrote :

I've now experienced this (after a few screen adjusts then logout/login again) on
- hp dc7700 (c2d-e6320, 8gb amd/ati rv610/radeon hd2400 pro/xt)

Lubuntu live...

( Of note, on this box I experienced more often than this issue... again openbox related maybe though )

Revision history for this message
Chris Guiver (guiverc) wrote :

Also experienced this now on
- dell [optiplex] 780 (c2q-q9400, 8gb, amd/ati cedar radeon hd 5000/6000/7350/8350)

I experienced 1845756 first... but adjusting screen again (esp. vertical alignment, one screen above the other) & had one display impacted by 1845756 and the other 2013074 (and lost my access to panel..)

moving mouse-pointer to GREY display (black display unusable) and I could right-click to cause OPENBOX TO RESTART, then I had LXQt menu & could open qterminal.... (kill etc)

description: updated
Revision history for this message
Chris Guiver (guiverc) wrote :

Also experienced on
- lenovo thinkpad x201 (i5-m520, 4gb, i915)

2 monitor alignment changes before I experienced (external monitor is attached)

i `sudo apt install xfwm4` ; at terminal started lxqt-config-session to replace openbox with xfwm4 & killed lxqt-session (panel was on 'black' monitor), on next login (ignoring the picom crashed too many times message) session was back to usable.

Revision history for this message
Aaron Rainbolt (arraybolt3) wrote :

There's an Openbox dev with a special "work" branch separate from normal upstream Openbox (I believe). He's got quite a few changes in there, I wonder if any of them affect this. I might try throwing a Git build of that into a PPA and asking for testing, if it works we can git bisect and figure out what fixes the problem, then patch things in Lubuntu and forward the patch to Debian.

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