It sounds like the Chief Architect program doesn't have proper access to record/capture the screen on your Mac. When a program attempts an action that requires certain access, such as recording/capturing the screen, your operating system will prompt you to either "Open System Preferences" or "Deny" the program permission. If you didn't select "Open System Preferences" and grant screen recording access to the Chief Architect program or the option to grant access never appeared, the built-in Screen Capture tool will function as you've described. Fortunately, you can easily change screen recording access through your Mac's System Preferences at anytime. For additional information on how to do this, please see the forum post linked below.