second monitor messed up sound output

I tried a second monitor in AI and got it connected via thunderbolt2 Mac. But now Cubase has NO sound…it has audio signal and I checked all
ins and outs…they are ok… but NO sound coming out on either the computer speakers or RT2 headphones…sound is ok outside of Cubase…
did it mess with the licenses??? I checked my eLicenser and it looks ok… what is going on??

Hi,

Does the screen has HDMI? Maybe there is also HDMI audio device?

Is it reproducible with all projects or only one project?

Double check, Cubase has enabled Mic in the System Preferences, please.
Open macOS System Preferences > Security & Privacy > Privacy > Microphone. Enable Cubase here.