I'm having same problem here. It must be a moderately recent windows update patch that caused this, because I've been having it for a couple of weeks, and my co-worker is now experiencing it since I ran Update on his PC.
We tried your solution, and it did not work, at least initially. I'll try to see if it improves.
My solution was more of a PITA. I created a sketch in the part to include the hidden edges I wanted to show, when Converted Entities in the drawing from the sketch onto the sheet as a hidden line Layer. It was tedious, and once I was completed with my drawing, ultimately unnecessary. That's because, although it would not show me the hidden lines on the view on monitor, it still produced them in the Save_As Adobe PDF result.
It appears inconsistent in its error and its fix. (Edit: I summarized this above as "same problem". This means 2016 SP3 as well. I neglected to make this clear.)
One other thing depending on how complex the drawing/model your working with is, it maybe as simple as restarting your computer or SolidWorks as min geeks out visually and I am running a NVidia M5000 video card and I have had all sorts of weird things go on and once I restart everything pops to how it should be. Almost reminds of the drawing bug that makes your views disappear until you toggle them to solid and back to wire frame.
Also note each view you have to either set to "High Quality" or "Link to Parent".
Hope this helps you figure it out.
I'm having similar issues with Solidworks 2017 SP05. I noticed that parts that I could not make visible (right click in tree --> hide/show --> show hidden edges) were visible for a fraction of a second and would then be completely invisible again. I found that in my case these were patterned parts hidden behind other (but identical) patterned parts. I could only make the front patterned part visible, the one behind it could not be made visible.
Maybe this helps someone. It is incredibly annoying though that this happens. In some cases I use the function "Alternate position view" with a special configuration of whatever I am trying to show the hidden edges of. I have also had the issue that several lines were indeed visible, but some were not.