Ha! I found it!
I too had this same problem, couldn't figure out why in the heck everything
was working fine, but I couldn't see it.
If you have it, press the little "e" on the top of your keyboard, or open
the "empowering" tools, I think they're called.
I feel like such an idiot, but here is what happened to me:
I wanted to be all technical and make everything on my laptop very secure,
so I "locked" all my devices, not knowing what that meant. Well, it does just
what it says!
See if this is your problem, because it was mine and it sounds exactly the
same.
You click on the little padlock looking thing and unlock your devices, and
they show right back up.
