I opened Blender in Terminal as you suggested and saw it rendering each individual object. It just took a few minutes to complete. Thanks!

I'm having the exactly same problem as the original poster with Blender 2.91 on Macbook Pro Catalina 10.15.7. When I click "render presets thumbs" I get the spinning wheel and I can see instances of blender opening and closing over and over again in my tray.