I'm not sure how to describe this, so it's hard to search for solutions.
I'm setting up MEP floor/ceiling plans (linked Arch model) and having a hard time with View Range/View Template/Visibility Graphics. Now I'm afraid it's a graphics card issue. In the two attached screenshots, no settings were changed. When zoomed out, everything looks OK, but roll the mouse wheel two clicks and I'm getting linework from other floors.
Any ideas what settings could be the culprit, or is it a hardware issue?