ubuntu mate - change monitor.preferences and 2 displays became 4/6/...

On initial adjustment of Monitor.Preferences & position of displays (instead of side-by-side, my top-bottom arrangement) the display remained mucked up a long while before it settled.. ie. it looked like this attachment.

Given time - all settled except the Monitor.Preferences issue this bug is about.

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/1934752

Experienced this again today on live QA-test (Ubuntu-MATE 2021-10-07 ISO) on

- hp dc7700 (c2d-e6320, 5gb, nvidia quadro nvs 290)
- hp 8200 elite sff (i5-2400, 8gb, nvidia quadro 600)

On the hp8200 the acer display started flashing on moving the mouse (which was on other display); otherwise same effect on both boxes

Also experienced the first part of this (trails & multiple green/red boxes very badly) today on

which was reported at https://bugs.launchpad.net/ubuntu/+source/ubuntu-mate-meta/+bug/1946413 (no loss of second display/wallpaper nor flashing experienced on nvidia)

QA-test install on (Ubuntu-MATE jammy)
- hp dc7700 (c2d-e6320, 5gb, nvidia quadro nvs 290)

install went well; on first login I adjust displays to match my setup & here my screens went haywire.

The Monitor.preferences box is now a mess with multiple screens shown ; and one display is a poor-reception-digital-tv type of blocky-mess..

If I move mouse around one display is flashing (when it's moved over anything I can select; if it's background or part of window were I cannot perform actions there is no flashing on the other display)..

On closing the Monitor.Preferences dialog the other display returned to normal.. Issue is apparent when Monitor.Preferences is opened & after making a change (WITH this nvidia video driver I suspect)

The install though was perfect.

On switch (MATE-Tweaks) from

WM: Marco (Adaptive compositor)

to

WM: Marco (No compositor)

I could NOT re-create the issue described in this bug report.

--

On returning to Marco (Adaptive Compositor) issues could be re-created (though not always; some took 2-3 moves (screen position relative to one another) before issue appeared, then it repeated)..

As I'm typing this, the horrific-flashing screen on the screens to my left (the QA-test box) has stopped flashing & re-drawn perfectly..

(of note: the dc7700 & hp 8200 share screens with one positioned above the other; not the more conventional left-right setup)

Booting same Ubuntu-MATE jammy daily on
- dell [optiplex] 780 (c2q-q9400, 8gb, amd/ati cedar radeon hd 5000/6000/7350/8350)

and issue occurs here too

(see screenpics on this & subsequent comment. this is after first change (swap left-right to match the way this box is setup, the pic in next.comment is my-right-changed-to-portrait)

second pic from dell 780 (radeon graphics card so not nvidia related)

note: Sorry, I may have reversed order of upload of pics

Ubuntu-MATE jammy live test on
- hp 8200 elite sff (i5-2400, 8gb, nvidia quadro 600)

identical effects as seen on hp dc7700

Note: box shares screens with dc7700 so Monitor.Preferences should be ~identical

Status changed to 'Confirmed' because the bug affects multiple users.

Affects me on SL500 with two monitors.

Are we talking here about https://github.com/mate-desktop/mate-control-center/issues/673 ?

I've now seen the upstream https://github.com/mate-desktop/mate-control-center/issues/687 as duplicate of #673 (https://github.com/mate-desktop/mate-control-center/issues/673) which itself is a a duplicate of much older #273 (https://github.com/mate-desktop/mate-control-center/issues/273)

Sorry I'm processing email in order.. and thus hadn't see the connections yet...

This comment upstream is a workaround - https://github.com/mate-desktop/mate-control-center/issues/273#issuecomment-446536228

I'll add something to the Yaru MATE themes.

It still affects me on VirtualBox with two virtual screens.

This bug was fixed in the package ubuntu-mate-artwork - 22.04.2

---------------
ubuntu-mate-artwork (22.04.2) jammy; urgency=medium

  * Sync Yaru-MATE themes/icons with upstream Yaru.
  * Fix Monitor Properties (LP: #1934752)

 -- Martin Wimpress <email address hidden> Wed, 02 Mar 2022 14:27:12 +0000