Bug 470411

Created attachment 159319 [details]
low resolution on 2º screen

SUMMARY
When turning on/restarting/suspending one of the screens returns with low resolution (640x480). This behavior is random (it doesn't always happen).
I have two HP V206hz monitors that have a maximum resolution of 1600x900x60hz and are connected to a Radeon RX 6600 via cable (displayport > DVI).
Wayland does not allow resolution change (attachment).

NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports

Search bugs on google
https://forums.gentoo.org/viewtopic-p-8782847.html?sid=709763f992be9f655473ea850ef7b784

The dmesg and xorg.0.log files
https://pastebin.com/u/anarcochip/1/znbvbyhU

STEPS TO REPRODUCE
1. Turn on, restart, or suspend your computer.
2. Power on, restart, or wait for the hibernation process to complete (front panel LED flashes).
3. Wait for the login screen or press any key to wake up the computer.

OBSERVED RESULT
One of the screens returns with a resolution of 640x480.
In some moments the screen with low resolution changes the color scale to 16bits (I suppose), in these moments, sometimes the screen changes and goes black, but it remains "on" (the monitor's led does not blink).
This behavior is random (doesn't always happen) and happens randomly on both monitors, sometimes the 1st sometimes the 2nd.
Sometimes restarting resolves the issue.

EXPECTED RESULT
Both screens turn on with resolution set to 1600x900x60hz.

SOFTWARE/OS VERSIONS
Windows: This behavior is not observed on win11 system
macOS: Not tested
Linux/KDE Plasma: Kubuntu 23.04
KDE Plasma Version: 5.27.4
KDE Frameworks Version: 5.104.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
I noticed that kwin related issues were not answered on Ubuntu's bugs.launchpad.net so I decided to move to Kubuntu-23.04 which wants to support multi-screem