today a customer called, he bought a new Windows laptop, and installed Rhino 7 SR 19.
Pressing the Tab-key, or starting manually _SubDDisplayToggle says in the command line it switches the viewports to flat, but the viewports stay always smooth. He sees e.g. a SubD-Cylinder only smooth, never flat.
Have them run SystemInfo in that Rhino 7 and share that text file here or with tech@mcneel.com… my first guess is that the new computer came with old GPU drivers but I don’t think that should cause what you described.
it seams there was a misunderstanding with the customer. The laptop was not new, and was using an unsupported old Intel HD Graphics 3000 graphics card.
I’ve told him, that Rhino 7 doesn’t support this card.