I have a 27" iMac 2017 and since I updated to Catalina whenever I restart the computer the display goes to max brightness. This is driving me crazy as I am a photographer and have calibrated my display and it is important that the display keep a consistent brightness. And max is too bright.
I have unchecked the "Automatically adjust brightness" in display preferences. How can I get it to hold the brightness??
Please reset the NVRAM per the directions in PRAM and NVRAM Reset and if that does not work, please restart in Safe Mode per Use safe mode to isolate issues with your Mac - Apple Support
I have an iMac 2019 21.5" Retina and have the same problem.
I've already done the PRAM reset and that seemed to help for a short time but now the issue is back.
I have to adjust my brightness every time the computer reboots or wakes up from sleep.
I've turned off all the auto brightness adjust settings with no effect.
Auto-brightness broken and goes to max
