Hi Robert,
Welcome back - long time!
System keyboard shortcuts take preference. You may have noticed your dock appearing and disappearing while pressing opt-cmd-D?
Go to System Preferences > Keyboard and uncheck the box for the system shortcut. It will now respond as desired within ARCHICAD.
Cheers,
Karl
One of the forum moderators • AC 26 USA and earlier • MacOS 11.6.8, iMac Pro