This seems to have been triggered by attempting to edit a door in a detail view. Rhino(7) froze for a while after I double clicked the door, and when it came back to life after a minute or so, all the walls near the door no longer displayed in wireframe view. Walls from a different session display properly, as the Gif shows. The walls are all of the same style. Saving and reopening Rhino corrected the problem.
Do you still get this issue with the internal 2.11 version we sent to you?
I have accidentally (defaults to 7 on opening .3dm files) been working in 7 for a few days without the issue and will let you know if it occurs again with the latest.