can't change brightness displayport to hdmi #2491

[xgiovio]

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Describe the issue

Hello, 6800xt here with 3 output.
first monitor: Hdmi to hdmi monitor , brightness control ok
second monitor: displayport to hdmi, brightness control not working
third monitor: displayport to hdmi, brightness control not working (same monitor of the second one)

In windows, same setup with same card and monitor works without problems using apps like this
https://www.nirsoft.net/articles/change_monitor_contrast_command_line.html

Any helps?

Expected behavior

Bightness control should be ok

Anything else?

No response

Environment Information (please complete the following information)

- macOS version:14.2.1
- Mac model:Macpro7.1
- MonitorControl version:latest
- Monitor(s):3
- Monitor Cable(s)/Connection(s):check desc
- Apple Silicon/M1 (yes or no):no