I have a specific problem since the update to 11.6.2 - on the two updated Macs, virtually all CMYK profiles are no longer displayed / made available system-wide. But only since the update, which includes a Colorsync modification among other things. This does NOT affect the RGB profiles.
I have tried everything, even a reinstall of 11.6.2 via the recovery partition (11.6.2 DMG), safeboot, nvram, unfortunately without success.
Then I reproduced the problem on our old Mac Pro, which conveniently still had a virgin 11.6 Big Sur installation in it. There we put in our Xerox profiles, which were also recognized and made available.
Then we updated to 11.6.2 - and unfortunately the same problem occurred in this installation. Our profiles were gone, but funnily enough, so was the default CMYK profile from Apple itself. The experimental update to Monterey then solved the problem.
>>>> So at this point I can only warn everyone not to install 11.6.2 , because we were able to reproduce this on two devices (the old Mac Pro and an iMac 5K from 2019) with three installations. The one who depends on different professional CMYK profiles in the PrePress area, should better skip this update, maybe a fix is still coming !
Addendum: We use Chronosync to keep the profiles on multiple Macs in sync, so all Macs access the same profiles in the same structures in the same locations. And yes, the permissions for these directories and profiles are clean and correct/unchanged).
Since we rewrite our printer profiles twice a year, we had the option to rewrite our CMYK profiles on a test basis, based on old profiles/measurements. With interesting results: While our previous version 4 (standard) profiles do not work, the somewhat slimmer rewritten profiles with the outdated version 2 are recognized without problems. (we profile with i1 Profiler).