Hello,
On the latest Rhino 9 BETA build (BETA (9.0.26258.12304, 2026. 09. 15.) on my Mac (M1 Max, Sequoia 15.7.5 (24G624)) I’m experiencing objects hiding unintentionally.
They are not deleted, I can show them again. It happens on Save (Cmd+S is tied to !_Save so it shouldn’t do hiding), on switching to other applications (e.g. I Cmd+Tab to my browser and back to Rhino, I routinely need to run Show to get back to where I was).
An example from the command history:
Command: Save
File successfully saved as Rhino 9 file file_path/model.3dm.
551 objects hidden.
I didn’t run the hide command but objects hide nonetheless. 
Any ideas on how to investigate what’s happening?
Thanks!