Surface Edge Display Bug

Version 8 WIP over the last few weeks and months has shown bizarre disappearance of (shaded mode) surface edges that depends on view rotation and zoom.

My document is much too big to upload yet a small portion of it exported as Rhino 8 and opened in a fresh Rhino session fixes the bug so it seems like the document itself is having the problem. It happens in many different files though, so it’s a consistent issue.’

Ah, I can resave the original document after deleting 90% of the objects then. And indeed the issue remains in the condensed version.
Rhino 8 WIP Disappearing Edges.3dm (976.7 KB)

Using 8.0.21196.305, 2021-07-15

Turning print preview on in the display pop-up menu fixes it. That’s my kludge for now then.