Bug 514859

Summary: Screen blanking after waking up from standby with Adaptive Sync set to automatic/ always
Product: [Plasma] kwin Reporter: Rynn <the.fallen.angel123>
Component: generalAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal    
Priority: NOR    
Version First Reported In: 6.5.5   
Target Milestone: ---   
Platform: CachyOS   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Rynn 2026-01-20 10:02:58 UTC
SUMMARY

When adaptive sync is set to either automatic or always, after the monitor goes into standby (Power Management > Turn off screen), after waking up, under certain conditions, it blanks for a second - goes dark, then back. I can confidently reproduce it with playing a youtube video and exiting / entering full screen, or taking a screenshot with Spectacle, and sometimes just opening / exiting apps such as system settings. The "fix" is to change refresh rate, e.g. from 240hz to 120, then back to 240.

STEPS TO REPRODUCE
1. Go into System Settings - Power Management; Set Turn off screen to 5 minutes / when locked, 2 minutes
1.1. Lock screen automatically: 5 minutes
2. Go to Display & Monitor; Change Adaptive Sync to Always (easiest to reproduce), or Automatic (most of the time it happens in automatic mode, too)
3. Leave your PC alone, so the monitor turns off and enters standby
4. Wake up the monitor, log in (move mouse for example)
5. Go to youtube and exit / enter full screen, or take a screenshot, or open / close / maximize apps

OBSERVED RESULT

Screen blanking upon entering / exiting youtube fullscreen 

EXPECTED RESULT

Not blanking screen.

SOFTWARE/OS VERSIONS
Operating System: CachyOS Linux 
KDE Plasma Version: 6.5.5
KDE Frameworks Version: 6.22.0
Qt Version: 6.10.1
Kernel Version: 6.18.6-1-cachyos-bore-lto (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 5800X3D 8-Core Processor
Memory: 32 GiB of RAM (31.2 GiB usable)
Graphics Processor 1: NVIDIA GeForce RTX 3070
Graphics Processor 2: NVIDIA GeForce RTX 5070 Ti

ADDITIONAL INFORMATION
Comment 1 Vlad Zahorodnii 2026-01-21 14:44:19 UTC
This seems like a driver bug. Please report this issue to graphics driver developers.