Created attachment 182792 [details]
Debug Log for powerdevil and kwin (6.4.1)

SUMMARY

External monitor wakes up unexpectedly after powerdevil turns off both displays during screen lock

STEPS TO REPRODUCE
1. Lock the screen (with two monitors connected - laptop built-in and HDMI external)
2. Wait 1 minute for powerdevil to turn off both displays
3. Observe behavior after approximately 30 seconds

OBSERVED RESULT

1.Both displays turn off simultaneously after 1 minute of screen lock (expected)
2. After ~30 seconds, computer emits two consecutive beep sounds
3. External HDMI monitor wakes up automatically while built-in display remains off
4. External monitor stays on indefinitely

EXPECTED RESULT

1. Both displays should remain off during entire screen lock period
2. Neither display should wake up without user interaction

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 41
KDE Plasma Version: 6.4.1
KDE Frameworks Version: 6.15.0
Qt Version: 6.8.3

ADDITIONAL INFORMATION

See attached logs for details.

PS: Behavior stops when downgrading kwin from 6.4.1-1 to 6.3.5-2 (beeps persist but display stays off)