Bug 506050

Summary:	Monitor settings don't save
Product:	[Plasma] kwin	Reporter:	Mateo Čić <mateo.cic05>
Component:	output configuration	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	mateo.cic05, nate, xaver.hugl
Priority:	NOR	Keywords:	multiscreen
Version First Reported In:	6.4.0
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Mateo Čić 2025-06-23 14:15:11 UTC

SUMMARY
I use laptop with closed lid and external monitor. When I turn on the laptop, monitor scaling is 70%. If I change it to 120% it works as intended but after turning off the laptop and then back on it resets to 70%.

STEPS TO REPRODUCE
1. Turn on the pc
2. Set monitor scaling to 120% and apply.
3. Reset the pc.

OBSERVED RESULT
Monitor scaling is 70%.

EXPECTED RESULT
Scaling should be 120%.

SOFTWARE/OS VERSIONS
KDE Plasma Version: 6.4.0
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1
Kernel version: 6.15.3-arch1-1

ADDITIONAL INFORMATION

Comment 1 Nate Graham 2025-06-24 18:36:15 UTC

I can't reproduce this with my laptop and external monitor hardware.

Comment 2 Mateo Čić 2025-06-24 18:50:23 UTC

(In reply to Nate Graham from comment #1)
> I can't reproduce this with my laptop and external monitor hardware.

Do you have lid shut or use both monitors? When I turn on the laptop, I shut the lid and use only external monitor.

Comment 3 Mateo Čić 2025-06-24 21:11:01 UTC

Opening and closing the lid also resets scaling to 70%. When lid is opened displays are configured so the external monitor is replica of built-in screen. 

Settings:

Built-in screen:
Resolution: 1920x1080
Scale: 100
Refresh rate: 144.0 Hz
Replica of: none
Legacy applications: Apply scaling themselves

External:
Resolution: 1920 x 1080 (Native is 1360 x 768)
Scale: 120 (Resets to 70.8333)
Refresh rate: 59.94 Hz
Replica of: none (Built-in screen when lid is opened)
Legacy applications: Apply scaling themselves

Comment 4 Nate Graham 2025-06-24 21:42:12 UTC

Aha, that's super relevant. Does the problem stop happening if you make the external monitor not be a replica of the built-in screen? This should be completely fine since for your use case, only one screen is ever active anyway, so making be a replica of others isn't needed and only triggers bugs in the replica feature.

Comment 5 Mateo Čić 2025-06-24 22:38:02 UTC

(In reply to Nate Graham from comment #4)
> Aha, that's super relevant. Does the problem stop happening if you make the
> external monitor not be a replica of the built-in screen? This should be
> completely fine since for your use case, only one screen is ever active
> anyway, so making be a replica of others isn't needed and only triggers bugs
> in the replica feature.

Yeah, that solves it.
 Kinda weird behaviour since it was replica of none by the time it loads to desktop. So you would expect it would be correct scaling. In any case, thanks for the assist.

Comment 6 Nate Graham 2025-06-24 22:44:13 UTC

You're welcome!

*** This bug has been marked as a duplicate of bug 481222 ***