@shafferw - I know you resolved this issue with a reset of your hard drive. I ran into the issue today, whereby the Security and Privacy settings for Zoom and Skype were there yesterday, but gone today.
After rebooting and full shutdown and restart, the Security and Privacy settings would not return! I figured that if the settings were correct before, then there maybe some corruption in the settings file or elsewhere on the hard drive. After running, Disk Utility > First Aid, then Rebooted, the Security and Privacy settings returned.
Zoom, Skype, FaceTime, etc settings re-appeared and worked just like the previous day.
I hope this easy solution helps someone. Also, I recommend running Disk Utility > First Aid at least once a month, to keep Mac OS running happy.