SDDM brief green/black split screen on Fedora 43 KDE

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Description:
On a fresh Fedora 43 KDE installation, the SDDM splash screen briefly displays incorrectly for 1-2 seconds: the screen is split vertically, with the left half green and the right half black. After this brief period, the login screen displays correctly and I can log in and use the system normally.

Hardware:

  • GPU: VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Picasso/Raven 2 [Radeon Vega Series / Radeon Vega Mobile Series] (rev c8)

Steps to reproduce:

  1. Boot Fedora 43 (fresh install, kernel 6.19.6, Wayland).
  2. Observe SDDM splash screen: briefly split vertically (left green, right black) for 1-2 seconds.
  3. Screen then corrects itself and login proceeds normally.

Additional info:

  • Fedora version: 43 (fresh install)
  • Kernel version: 6.19.6 (after update)
  • Display manager: SDDM
  • Session type: Wayland

I can provide logs or further details if needed.
Best regards

Additional observations:

  • The issue does not occur with GDM on the same machine.
  • The issue does not occur in a virtual machine using SDDM.
  • The issue does not occur on another physical PC with a similar setup.
  • The issue also appears briefly during shutdown, showing a similar graphical glitch.
  • Plymouth displays correctly before SDDM starts, indicating the problem likely happens during the transition to SDDM.