I have a model with a terrain and extruded objects. I've set up a few cameras/view and created viewports. Some work with openGL and other do not (everything disappears). The non-working viewports can render in hidden line. When in the design layers, I can "activate camera view" and render in openGL in design space and it works.
I am using VectorWorks2020 on macOS High Sierra 10.13.6