Bug 507344

Summary: "Global scale" changes do not apply to existing windows
Product: [Applications] systemsettings Reporter: Alexander Potashev <aspotashev>
Component: kcm_kscreenAssignee: kscreen-bugs-null <kscreen-bugs-null>
Status: RESOLVED DOWNSTREAM    
Severity: normal CC: plasma-bugs-null
Priority: NOR    
Version First Reported In: 6.3.4   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Alexander Potashev 2025-07-22 07:55:43 UTC 
SUMMARY
"Global scale" changes do not apply to existing windows.

STEPS TO REPRODUCE
1. Open Display Configuration KCM
2. Change Global scale from 100% to 125%, click Apply
3. Open Dolphin
4. Change Global scale from 125% to 150%, click Apply
5. In Dolphin, click File -> New Window.

OBSERVED RESULT
The KCM window didn't change scale. Dolphin window #1 is at 125%. Dolphin window #2 is at 150%.

The current behavior requires more clicks to preview the scale while adjusting it: you have to repeatedly
 1. adjust scale
 2. run new application / open new window
 3. close that window to cleanup.

It also requires saving the data in all open apps and restarting them after having set the scale to the desired value.

EXPECTED RESULT
Step 2 should change scale of the KCM window to 125% when clicking Apply. Step 4 should change the scale of both windows (KCM and Dolphin).

SOFTWARE/OS VERSIONS
Operating System: Debian GNU/Linux rodete 
KDE Plasma Version: 6.3.5
KDE Frameworks Version: 6.13.0
Qt Version: 6.8.2
Kernel Version: 6.12.27-1rodete1-amd64 (64-bit)
Graphics Platform: X11
Processors: 14 × Intel® Core™ Ultra 7 165U
Memory: 62.3 GiB of RAM
Graphics Processor: Intel® Graphics


ADDITIONAL INFORMATION
Comment 1 Bug Janitor Service 2025-07-22 10:44:11 UTC 
Thank you for the bug report!

However Plasma 6.3.4 no longer receives updates or maintenance from KDE; active versions are 6.4 or newer. Please upgrade to an active version as soon as your distribution makes it available to you. Plasma is a fast-moving project, and bugs in one version are often fixed in the next one.

If you need help with Plasma 6.3.4, please contact your distribution, who bears the responsibility of providing help for older releases that are no longer receiving updates from KDE.

If you can reproduce the issue after upgrading to an active version, feel free to re-open this bug report.