SUMMARY

When I connect my laptop to a TV, with the extended mode, both my laptop's internal display and my external monitor (XMD Mi TV) work correctly and can be set to their respective native resolutions.

However, when I switch the display mode to "Mirror," the following problem occurs:

1. Internal Display: Appears completely normal with the correct resolution.
2. External Monitor (XMD Mi TV): Shows severe abnormalities. Its resolution becomes very low (far below its native resolution), causing the image to be blurry, stretched, and compressed, making it almost impossible to see the content clearly.

STEPS TO REPRODUCE
1. Connect the external monitor (XMD Mi TV) to the laptop.
2. Set the display mode to "Extended." Both displays should now be working normally.
3. Switch the display mode to "Mirror" (or "Clone").
4. Observe the external monitor. You will see its resolution drop significantly, becoming blurry and compressed, while the internal display remains unchanged.

OBSERVED RESULT

In mirror mode, the external monitor is forced to use an extremely low and incorrect resolution, while the internal display remains unaffected. It appears that KDE/Wayland's mirroring logic is incorrectly applying the low resolution or faulty EDID information from the internal display to the external monitor.

EXPECTED RESULT

In mirror mode, the system should automatically select an optimal common resolution supported by both displays, or at least allow the user to manually set a common resolution to ensure both screens can display clearly.

SOFTWARE/OS VERSIONS

Operating System: openSUSE Tumbleweed 20251110
KDE Plasma Version: 6.5.2
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Kernel Version: 6.17.7-1-default (64-bit)
Graphics Platform: Wayland
Processors: 22 × Intel® Core™ Ultra 7 155H
Memory: 32 GiB of RAM (30.8 GiB usable)
Graphics Processor: Intel® Arc

ADDITIONAL INFORMATION

I have attached four images: