Can't adjust Apple display brightness connected to 2020 M1 Mac Mini
I recently migrated from a 2018 Mac Mini to a 2020 M1 Mac Mini, both running Ventura 13.7.8. With each I was using the same 27" Apple Cinema display and the same wired Apple keyboard. With the 2018 Mac Mini I was able to change the display brightness either via the keyboard or via the Displays System Settings. However, with the 2020 Mac Mini, there is no response to the keyboard brightness buttons, nor is there any brightness adjustment available in the Displays System Settings. The 2020 M1 Mac Mini recognizes that it is connected to the Cinema Display, and both the display's DisplayPort and USB cables are connected to the system, and yes I have tried restarting my Mac with no change.
Is there a hidden setting that I need to enable, or is the display brightness feature not compatible with the newer Apple Silicon Macs when used with older Apple displays? Thanks.
Mac mini (M1, 2020)