MP 1,1-5,1 Monitor Brightness Keys don't work after sleep

[minifridge1138]

Hello everyone,

Immediately after my Mac boots, the monitor brightness keys on the keyboard work and I can adjust the brightness of either of my displays.
Every time my Mac Wakes from sleep, the brightness keys on the keyboard do not work. The physical buttons on the monitor still work. As a workaround, if I kill the 'corebrightnessd' process (/usr/libexec/corebrightnessd), then the system will re-launch the daemon and then the keyboard buttons will work until it goes to sleep.

Does anyone have any ideas or suggestions? Right now I just manually find and kill the PID of that process. I'm sure I could write some sort of script to kill it for me, but obviously something is broken because this isn't supposed to happen.

Thanks!

I have a relatively standard modded setup - MP 4,1 flashed to 5,1 with 2 X5680 and 128 GB of ram. I'm running firmware 144.0.0.0.0 and macOS Mojave 10.14.6. I have a Mac Edition HD 7950. For monitors, I have 2 30" Apple Cinema Displays.

 

[Eneco]

I had the same problem and found out, that the USB cable of the monitor, which handles the brightness control, has to be connected to one of the internal USB 2.0 ports. If you connect it to a PCIe USB 3.0 card it will always stop working after sleep.

 

[minifridge1138]

That was it!
My monitors' USB cable was connected to a PCIe card (2.0 not 3.0) and everything works after moving them around.
THANK YOU!