I am experiencing the following strange display behavior in Rhino WIP, and want to report it as a bug:
Switching to wireframe & back doesn’t cause it to re-draw the display meshes properly, nor does the “refreshshade” command. you can see the terrain surfaces are properly displayed in the wireframe viewport mode:
I went to the YouTrack page, but it was unclear how to post bug reports there.
Any guidance would be most appreciated 
We’re not yet setup for users to directly add reports to YouTrack.
We need a small, clear description of the problem and a concise, specific sequence to follow that demonstrates the issue, together with any files if needed.
You can post them here if that’s convenient.
Thanks
Well, in addition to the screenshots posted, I can add the procedure of what I had done and some file references then:
I had created nine “drape” surfaces over a reference STL mesh, which was 600mmx600mm and positioned with the bottom-left corner on the origin.
The drape commands were run with auto sampling density of “1” and covering a 3x3 grid of 200x200mm each, so I ran the drape command nine times in the top view, with the zoom set to fit extents of the mesh:
[0,0 to 200,200], [200,0 to 400,200], [400,0 to 600,200] and so on for 200 to 400 Y, and 400 to 600 y.
Then, due to edge alignment errors in the drapes, I created nine rectangles in plan view to trim the surfaces, to then create blend surfaces between the adjacent “tiles”:
A rectangle from [1,1 to 199,199], from [201,1 to 399,199], and so on.
I then trimmed the surfaces back, and proceeded to create the blend surfaces, but when I zoomed out after creating one or two of the blends I noticed the mesh display error, which was not alleviated by a re-draw nor transitioning to wireframe view and back.
I saved the scene, exited, and then reopened Rhino and reloaded the scene and the issue was resolved.
Here’s the reference mesh and resulting surface set (with blend surfaces completed, albeit with some issues) if you wish to replicate my process:
Hi again
I’ve just been corrected. You can add the bug report yourself.
Go to https://mcneel.myjetbrains.com/
Sign up for a new account and you’re in.
Thanks