MonitorControl: LG HDR 4K monitor Contrast-control slider stopped working (no change in hardware or MonitorControl.app)

Before opening the issue, have you…?

• Searched for existing issues
• Read through the Monitor-Troubleshooting Wiki
• Updated MonitorControl to the latest version (if applicable)

Describe the issue

LG HDR 4K monitor (LG 32UL500, full specs: https://i.imgur.com/uPQ2wFC.png; advanced settings: https://i.imgur.com/sj4ZV8X.png) Contrast-control slider stopped working after no other, apparent change in hardware or MonitorControl.app v4.1.0 app. Downgrade to MonitorControl.app v3.1.1 (Build 3096) has same symptom.

Everything worked prior to 2022-005 Catalina security-patch upgrade and Safari 13.x --upgrade_to–> 15.x. Constrast-slider stopped working after. Brightness and Volume controls work. Everything on AOC U3277WB monitor (same MacBook) works.

Another user reports similar behavior when upgrading macOS 12.5.4 -> 12.6 on a LG 32BL95-U-W 4K monitor.

Expected behavior

Contrast-changing slider should work.

Anything else?

No response

Environment Information (please complete the following information)

MonitorControl.app v4.1.0

system version (edited 2022-09-21 after 2022-005 Catalina security-patch upgrade):

$ sw_vers
ProductName:	Mac OS X
ProductVersion:	10.15.7
BuildVersion:	19H2026
$