Unable to modify monitor brightness on BenQ EX2710Q.

[RokeJulianLockhart]

I'm reporting this on behalf of @jaredrichardwilliam.

Errata

He recently replaced his AOC Q3279WG5B. That AOC monitor could be controlled via https://github.com/xanderfrangos/twinkle-tray/releases/download/v1.16.3/Twinkle.Tray.v1.16.3.exe and the KDE Plasma 6.2 Brightness plasmoid (which is dependent upon https://fedora.pkgs.org/40/fedora-updates-x86_64/powerdevil-6.2.2-1.fc40.x86_64.rpm.html, unlike TT).

His new monitor, a BenQ EX2710Q, can have its brightness modified by the plasmoid, but cannot via Twinkle Tray, for although it successfully establishes a connection, the actual brightness of the display does not alter.

Environment

1. Get-ItemProperty -LiteralPath 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion' | Format-List

2. SystemRoot                : C:\WINDOWS
   BaseBuildRevisionNumber   : 1
   BuildBranch               : ge_release
   BuildGUID                 : ffffffff-ffff-ffff-ffff-ffffffffffff
   BuildLab                  : 26100.ge_release.240331-1435
   BuildLabEx                : 26100.1.amd64fre.ge_release.240331-1435
   CompositionEditionID      : Enterprise
   CurrentBuild              : 26100
   CurrentBuildNumber        : 26100
   CurrentMajorVersionNumber : 10
   CurrentMinorVersionNumber : 0
   CurrentType               : Multiprocessor Free
   CurrentVersion            : 6.3
   DisplayVersion            : 24H2
   EditionID                 : Professional
   EditionSubManufacturer    :
   EditionSubstring          :
   EditionSubVersion         :
   InstallationType          : Client
   InstallDate               : 1725799783
   LCUVer                    : 10.0.26100.2152
   ProductName               : Windows 10 Pro
   ReleaseId                 : 2009
   SoftwareType              : System
   UBR                       : 2152
   PathName                  : C:\Windows
   PendingInstall            : 0
   ProductId                 : 00331-10000-00001-AA566
   DigitalProductId          : {164, 0, 0, 0…}
   DigitalProductId4         : {248, 4, 0, 0…}
   RegisteredOrganization    :
   InstallTime               : 133702733830607009
   PSPath                    : Microsoft.PowerShell.Core\Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
                               NT\CurrentVersion
   PSParentPath              : Microsoft.PowerShell.Core\Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT
   PSChildName               : CurrentVersion
   PSDrive                   : HKLM
   PSProvider                : Microsoft.PowerShell.Core\Registry

[RokeJulianLockhart]

#869 (comment)

I've tried going to a slightly lower level to confirm that it's an issue in TT, but the result was not what I hoped. Consequently, I've filed MartinGC94/MonitorConfig#1 (comment). However, considering that it's unlikely to be a dependency of yours, I'm beginning to wonder whether this is an issue with an underlying Windows API or the monitor's DDC/CI conformance.