A critical regression can occur in KWin (Wayland) where Plasma repeatedly crashes or fails to initialize correctly on systems using newer AMD graphics cards (such as the Radeon RX 9070).
This issue produces the following error messages in the system logs
amdgpu: [drm] *ERROR* Unsupported screen format RA24 little-endiankwin_wayland: Atomic modeset commit failed! Invalid argumentkwin_wayland: Applying output configuration failed!Until a permanent upstream patch is applied to the system packages, you can force KWin to use a software-based mouse cursor instead of hardware-driven DRM rendering. This bypasses the faulty screen format initialization.
Open the global environment configuration file in a terminal:
sudo nano /etc/environment
Manually add the following line to the bottom of the file:
KWIN_FORCE_SW_CURSOR=1
Save the file (Ctrl+O, Enter) and exit the editor (Ctrl+X).
Reboot your system to apply the changes.