I'm making a small restaurant mockup. I setup some basic tables and chairs. There are some scaling issues in this scene due to some LiDAR scanning, so the scale of the chairs was huge. I converted them to mesh and they reappeared in the viewport. They did NOT appear in any render however. When you convert some models, Cosmos included, sometimes it makes some sort of parent object and a child. You can't select anything on the parent and it has the material on it. I don't understand how that works.
So, I merged those two pieces of the chair into one mesh. Boom. Everything appears and renders as expected. Render Instances or Multi-Instance don't affect this issue.
Since this sample scene is so small, I've attached it directly here. This scene is new and there are no scene scaling issues.
Corona v11
Nov 29 2023 19:27:40
C4D r25
Mac OS 12.5.1 Monterey