Brightness adjustment disappears when switching to discrete graphics via MUX Switch

[Hera]

Hello ASUS Support Team,
I am experiencing an issue with my ASUS ROG Zephyrus G16 (GU603ZV) laptop. When I activate the discrete graphics through the MUX Switch, the ability to adjust the screen brightness disappears. The brightness is locked at a specific level, and adjusting it via function keys or Windows settings does not work.
I have recorded a video demonstrating the issue and attached a log for analysis. The video can be accessed via the Google Drive link: [ https://drive.google.com/drive/folders/1rh3df8Qr7HE1MK2EGWJbUrV5U_zv3qWt?usp=drive_link ] I have also attached the log that describes the situation in detail.
I kindly request your assistance in resolving this issue and providing a solution.
Thank you in advance for your help!

[Hera · Accepted solution]

Good afternoon, the issue has not been resolved. The laptop is unusable after updating VBIOS in MyASUS.

[Hera]

[Hera]

I contacted support, but the manufacturer was unable to reproduce the issue. The sequence is as follows: switch the system to Eco mode, restart the laptop, then switch the system to Standard mode. Adjusting the brightness will be impossible (after a reboot, everything returns to normal).

The issue with the half-turned-off screen was resolved by reinstalling Windows, but the brightness problem still remains even after upgrading to Windows 11 24H2. I want to switch to Windows 11 22H2 (since the ROG drivers on the official website are optimized for this version), but I can't find an ISO image of Windows 11 22H2.