Upgrading

Plasma 5.19.4 → 5.19.5
kscreen 5.19.4 → 5.19.5
Frameworks 5.73.0 → 5.74.0
Qt 5.15.0 → 5.15.1

results in problems with special dual screen setups where the DisplayPort-0 is the right screen and DisplayPort-1 is the left and primary screen.

STEPS TO REPRODUCE
1. Set up a workspace where the left screen contains a workspace view and the right screen contains a directory view.
2. Set up two control bars: the control bar on the left screen consists of a window bar which only shows windows of the screen. Same for the control bar on the right screen.
3. Upgrade the packages (for full package list, see packages.txt)
4. Restart

OBSERVED RESULT
After upgrading and rebooting, the workspaces are swapped: the right screen shows the workspace view and the left screen shows the folder view. The control bars on the other hand stay on the screen but show the windows for the wrong screen.

When switching the primary screen using kcm nothing happens. When performing this action again the workspace/folder views and/or control bars swap randomly. Sometimes, both window bars only show windows on the right monitor. After changing the screen positions and primary screen settings several times it eventually reaches the preferred state like before the upgrade. But only until a reboot/logout.

A downgrade fixes the problem.


EXPECTED RESULT
I except KDE/Qt to save the screen state during reboot.


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 5.19.5
KDE Plasma Version: 5.19.5
KDE Frameworks Version: 5.74.0
Qt Version: 5.15.1
X.org: xorg-server 1.20.9-2

As this might be a complex problem with a lot of interference between components or even KDE <-> Qt I submit this bug to KScreen initially because it is a problem with screen management. If this bug belongs to another component, I'm more than happy if you could move it there.