Selected edges not being drawn

[micheus]

The sites I found all felt shady. (There are multiple "download" links, most of which appear to be ads. I don't trust it very much.)

yeah, I hate that too. Here is the direct link.

If you add a triangle to the handle object, do the edges appear?

I didn't spend time with that. As I post in those links it's like a random situation that can vary for each user, but it seems always related to device drivers (you can read OpenGL manufacturer too). I'm trying to looking for a tip about it, but it can be very complicated.