Bug?: Lines with custom color disappear when zoomed

Problem Custom Color.3dm.zip (102.6 KB)

In the attached file I have a group of joined lines. They are set to have a custom color of orange (ie not by layer). I also have a line running through one of them with the color set to layer for reference.

When I zoom in, the orange lines disappear.

But I can select them even when I cannot see them:

If I change the color to BY LAYER then I can see them when I zoom.