Show imported Google events as busy in Mac Calendar

We use Mac / calendar / iCloud here at my company for time management. In my personal life, I use google Calendar. So I import my google calendar into my Mac Calendar. This works great, I can see all my events in one place. Problem: other people cannot see when I am busy on my personal calendar. The "Check Availability" option shows me as available during the times I have personal events. Here is a screenshot showing a concrete example. The blue event "PERSONAL EVENT" from 12PM to 1PM is my personal event. In the screenshot I am creating a new "WORK EVENT" from 2PM to 3PM. **You can see in the "Check Availability" window that my availability does not include the personal event. Why?** I found a setting in the imported calendar named "Event affects availability". It was already checked. The name makes me think that the imported calendar should already be affecting availability? But it is not. Is there any way for me to indicate that I'm busy for my imported Google events on my Apple Mac Calendar?