Adding jog to ortho cube wrecks viewport by adding non-existant hidden lines

[Anonymous]

I am trying to produce orthographic drawings in Plant 3D, and I'm having trouble getting structural steel members to display correctly in viewports.  I find that if I use an orthocube without jogs, the structural steel displays correctly (no hidden lines).  However, if I add any kind of jog (even one that does not in any way cut into any structural objects), it adds a ton of mysterious hidden lines that completely wreck the orthographic view, thereby making it completely unusable.  

Here is an example with two viewports. The top one displays correctly, the bottom one displays a great deal of hiddenlines that should not be there.

Here is the ortho cube I used for the top viewport:

And here is the one I used for the bottom viewport:

Note that the only difference between the two is the tiny jog in the upper right corner (which should in no way affect the appearance of the structural beams in the orthographic drawings).

[h_eger]

Dear @Anonymous,

1. Which plant 3d version?

2. Where does your steel construction come from?
Program and Version

3. Solids or surfaces?

[Anonymous]

The Plant 3D version is 2018, the steel is from AutoCAD 2018, and the beams are polyface meshes.