Studio Display Brightness Control & Sonoma & Studio Display Firmware Update 17
After updating my M1Pro MBP to Sonoma and my two Studio Displays to Firmware 17, I can no longer control the brightness of either studio display in clamshell mode. When I close the lid of my MBP and connect to the Studio Display, the Display's brightness is very low and I have not ability to turn up the screen's brightness--either from the keyboard shortcut or through Control Panel. The only way to resolve the issues is to restart my MBP each and everytime I conntect it to the Studio Displays. (Just to be clear, I have two studio displays...one at my office and one at home, this issue happens on both Displays; but I am not running two studio displays at once). It's like the MBP does not fully recognize that I have Studio Displays connected (absent a reboot with the displays connected). As you can see from the screen captures below, if I connect the displays and reboot the machine, the system recognize the Studio Display and I am able to make settings changes like turn on/off "automatically adjust brightness, etc." However, absent the reboot, as you can see from the last two screen shoots, the system does not pull the correct information in the System report, and all the feature options are missing in the Control pannel.
Here is a System report and Control Panel screenshot of when I reboot the MBP with the Studio Display connected--it is behaving correctly, and the system is able to see that it is a Studio Display and pulls the Firmware Version along with the SN, and in Control Panel you have the full range of feature settings
Here are the same screenshots, absent a reboot when the Studio Displays are not fully functional and very dim with no ability to brighten:
Studio Display