Are you in the air looking for GV's?
Or are you on the ground looking for GV's?
In the air, it's sometimes difficult to see GV's because the Icon can get hidden depending on the environment or situation.
You might also have accidentally turned off icons, which you can fix with Alt+I. Hit it until it says Normal Icons.
If you're on the ground looking for GV's, you won't see an Icon, as they don't have em.
You might also go to ground visibility, which is Shift+F4. And then you can switch back to full visibility with Shift+F1.
Hope that helps.