Ok. So I think I can say I'm not crazy. Roy's nested door exhibits the same problem. That's good news because it tells me my nested families aren't the problem. There must be something wrong with my installation of Revit. See attached example. Roy's door is on the left the one that looks good is the first insert, the other was mirrored. The window with transom is one that I built. The window by itself is Roy's and you can see mirroring a regular window works fine.
Notice how Roy's swing lines still show up on the mirrored instance but mine don't. I assume this has something to do with the plane that they are drawn in.
FYI, using detail lines within the nested component is totally unacceptable. I won't be able to do views shaded with edges like shown in this example (or use shadows).
How do I officially submit this problem to the factory? I assumed this forum was for that purpose but if there is a better way please let me know.
edited...I attached a project that has my nested windows in them and noted which one was original, the one that was mirrored and the one that was flipped. Can someone open this and tell me if you see the same problems I'm seeing?
Also, I installed the latest build and that doesn't solve the problem.
Thanks everyone for helping out with this.