When Advanced Optimus is Enabled in the BIOS, my screen gets locked to max brightness and cannot be changed.

I have tried everything I could think of. Reinstalling graphics drivers for both the integrated and dedicated graphics, the BIOS drivers, display drivers. I tried opening Windows in Safe Mode to see if it was a software issue. I updated Windows to see if it was an OS issue.

When Advanced Optimus is Disabled, this doesn't happen and I'm able to freely change the brightness of the screen. The dedicated GPU seems to be functioning fine, and I suspect it might be a hardware issue with the iGPU. I hope that isn't the case.

If anyone has any more solutions, that'd be a great help.